Flexible circuit board and manufacturing method, display device, circuit board structure and display panel thereof

ABSTRACT

This disclosure provides a flexible circuit board and a manufacturing method therefor, and a display device. The flexible circuit board includes a main body sub-circuit board and a bridge sub-circuit board. The main body sub-circuit board includes a first substrate, as well as a first bridge connection end, a second bridge connection end, a first wiring portion, and a second wiring portion disposed on the first substrate. The bridge sub-circuit board includes a second substrate, as well as a third bridge connection end, a fourth bridge connection end, and a third wiring portion used for a first functional wiring, all disposed on the second substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/418,771, which is based upon and claims the priority of PCT patentapplication No. PCT/CN2020/082216 filed on Mar. 30, 2020 which claimspriorities of Chinese application No. 201910093341.0, filed on Jan. 30,2019 and entitled “FLEXIBLE CIRCUIT BOARD AND MANUFACTURING METHOD,DISPLAY DEVICE”, Chinese application No. 202010075431.X, filed on Jan.22, 2020 and entitled “FLEXIBLE CIRCUIT BOARD AND MANUFACTURING METHOD,DISPLAY DEVICE”, and Chinese application No. 201911136276.1, filed onNov. 19, 2019 and entitled “CIRCUIT BOARD STRUCTURE, AND DISPLAY DEVICETHEREOF”, the entire contents of which are incorporated herein byreference.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a flexible circuit boardand a manufacturing method thereof, a display device, a circuit boardstructure and a display panel thereof.

BACKGROUND

The flexible printed circuit (FPC) is a highly reliable and flexiblecircuit board made of flexible thin film as a base material. Theflexible circuit board has high wiring density, good flexibility, and itis light, thin, and widely used in various electronic devices such asmobile phones, computers and displays.

The FPC in the OLED display panel generally includes display-relatedcircuits and touch-related circuits. It is necessary to minimizeoccupied space of FPC for limitation of the size of display panel.

In related art, the FPC generally adopts a design of six-layer soft andhard combination. The display-related circuits and the touch-relatedcircuits may be arranged in different laminated structures, so as toreduce the occupied space of FPC.

However, the structure design of a six-layer FPC is difficult, themanufacturing process thereof is complicated and the cost is high.Because of few corresponding manufacturers in China with not hightechnical capabilities, manufacturers abroad at present are primarysuppliers of the six-layer boards, but have long delivery period, sothat it is not convenient for the flexible operation of an project.

It should be noted that the information disclosed in the above“Background” section is merely intended to reinforce understanding ofthe background technology of the present disclosure, accordingly theBackground may include information that does not constitute the priorart as already known by an ordinary person skilled in the art.

SUMMARY

The present disclosure provides a flexible circuit board and amanufacturing method thereof, a display device, a circuit boardstructure and a display panel thereof, to solve the technical problemsof difficult design, complex manufacturing process and high cost of asix-layer board in related art.

Other features and advantages of the present disclosure will becomeapparent from the following detailed description, or in part, will belearned by practice of the present disclosure.

At least one embodiment of the present disclosure provides a flexiblecircuit board. The flexible circuit board includes a main bodysub-circuit board including a first substrate, and a first bridgeconnection end, a second bridge connection end, a first wiring portionand a second wiring portion on the first substrate, in which the firstwiring portion and the second wiring portion are separated from eachother and electrically connected to the first bridge connection end andthe second bridge connection end, respectively; a bridge sub-circuitboard including a second substrate, and a third bridge connection end, afourth bridge connection end and a third wiring portion for a firstfunctional wiring on the second substrate, in which the third bridgeconnection end and the fourth bridge connection end are electricallyconnected by the third wiring portion, the bridge sub-circuit boardbeing configured to be installed on the main body sub-circuit board byelectrically connecting the third bridge connection end and the fourthbridge connection end to the first bridge connection end and the secondbridge connection end, respectively, so that the first wiring portion,the third wiring portion and the second wiring portion are sequentiallyelectrically connected to obtain the first functional wiring; an outlineshape of the first substrate being different from that of the secondsubstrate.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, an outline shape of the bridgesub-circuit board is a symmetrical structure.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, an outline shape of the bridgesub-circuit board is an asymmetric structure.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the third bridge connection endand the fourth bridge connection end on the bridge sub-circuit board aresymmetrically arranged on both sides of the bridge sub-circuit board.

For example, the flexible circuit board provided by at least oneembodiment of the present disclosure further includes a first controlcircuit combination structure, in which the first control circuitcombination structure is disposed on the main body sub-circuit board andelectrically connected to the first wiring portion, or the first controlcircuit combination structure is disposed on the bridge sub-circuitboard and electrically connected to the third wiring portion; the firstcontrol circuit combination structure being configured to provide afirst electrical signal to the first functional wiring or receive afirst electrical signal from the first functional wiring.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardfurther includes a second functional wiring. The second functionalwiring is electrically connected to the first control circuitcombination structure on the main body sub-circuit board, the firstcontrol circuit combination structure is further configured to provide asecond electrical signal to the second functional wiring or receive asecond electrical signal from the second functional wiring.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the first functional wiring isobtained by sequentially electrically connecting the first wiringportion, the third wiring portion and the second wiring portion, and isused to transmit a touch driving signal, and the second functionalwiring is used to transmit a touch sensing signal.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the first functional wiring isobtained by sequentially electrically connecting the first wiringportion, the third wiring portion and the second wiring portion, and isused to transmit a touch sensing signal, and the second functionalwiring is used to transmit a touch driving signal.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardfurther includes a third functional wiring. The third functional wiringis between the first wiring portion and the second wiring portion, andthe bridge sub-circuit board is connected to the third functionalwiring. The first wiring portion and the second wiring portion passunder the bridge sub-circuit board for connection.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardfurther includes a third functional wiring. The third functional wiringis between the first wiring portion and the second wiring portion, andan orthographic projection of the third functional wiring on the firstsubstrate at least partially overlaps with an orthographic projection ofthe bridge sub-circuit board on the first substrate.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the third functional wiring isconfigured to transmit a signal different from that of the firstfunctional wiring and the second functional wiring.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the third functional wiring isused to provide a signal for a display circuit.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the third functional wiringextends to a side of the main body sub-circuit board and is electricallyconnected to a terminal at the side of the main body sub-circuit board.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the first wiring portion, thesecond wiring portion, and the third functional wiring are wired in asame direction.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardincludes a first main body wiring layer at a first side of the firstsubstrate, and a first main body insulating layer laminated on a side ofthe first main body wiring layer far away from the first substrate, andthe first side is a side of the main body sub-circuit board close to thebridge sub-circuit board. The main body sub-circuit board furtherincludes a second main body wiring layer at a second side of the firstsubstrate, and a second main body insulating layer laminated on a sideof the second main body wiring layer far away from the first substrate.A part of the first wiring portion is in the first main body wiringlayer, and another part of the first wiring portion is in the secondmain body wiring layer. A part of the second wiring portion is in thefirst main body wiring layer, and another part of the second wiringportion is in the second main body wiring layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, a part of the second functionalwiring is in the first main body wiring layer, and another part of thesecond functional wiring is in the second main body wiring layer, or thesecond functional wiring is all in the first main body wiring layer. Apart of the third functional wiring is in the first main body wiringlayer, and another part of the third functional wiring is in the secondmain body wiring layer, or the third functional wiring is all in thesecond main body wiring layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the second functional wiring isall in the first main body wiring layer, and the third functional wiringis all in the second main body wiring layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the first main body insulatinglayer has a first via hole that exposes the first bridge connection endand the second bridge connection end.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, at least a part of a wiring of thefirst wiring portion on the second main body wiring layer iselectrically connected to the first main body wiring layer through asecond via hole for electrically connecting to the bridge sub-circuitboard through the first bridge connection end, and at least a part of awiring of the second wiring portion on the second main body wiring layeris electrically connected to the first main body wiring layer throughthe second via hole for electrically connecting to the bridgesub-circuit board through the second bridge connection end.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardincludes a first main body wiring layer at a first side of the firstsubstrate, and a first main body insulating layer laminated on a side ofthe first main body wiring layer far away from the first substrate. Themain body sub-circuit board further includes a second main body wiringlayer at a second side of the first substrate opposite to the first sidethereof, and a second main body insulating layer laminated on a side ofthe second main body wiring layer far away from the first substrate. Thefirst main body wiring layer includes the first wiring portion, thesecond wiring portion, and the first bridge connection end, the firstbridge connection end is exposed by the first main body insulatinglayer. The second main body wiring layer includes the first wiringportion, the second wiring portion, and the second bridge connectionend, the second bridge connection end is exposed by the second main bodyinsulating layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardincludes a first bridge wiring layer at a first side of the secondsubstrate, and a first bridge insulating layer laminated on a side ofthe first bridge wiring layer far away from the second substrate, thefirst bridge wiring layer includes the third wiring portion.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardfurther includes a ground layer at a second side of the second substrateopposite to the first side thereof. When the bridge sub-circuit board isinstalled on the main body sub-circuit board, the second side is closerto the main body sub-circuit board than the first side.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardfurther includes a second bridge insulating layer laminated at a side ofthe ground layer far away from the second substrate. The second bridgeinsulating layer is provided with a plurality of openings exposing apart of the ground layer, and the plurality of openings serve as thethird bridge connection end and/or the fourth bridge connection end forelectrically connecting the bridge sub-circuit board to the main bodysub-circuit board.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardfurther includes a shielding layer at the second side of the secondsubstrate, and the shielding layer is laminated on a side of the groundlayer far away from the second substrate.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardfurther includes a second bridge wiring layer at a second side of thesecond substrate opposite to the first side thereof, and a second bridgeinsulating layer laminated on a side of the second bridge wiring layerfar away from the second substrate. The second bridge wiring layerincludes the third wiring portion, the third bridge connection end, andthe fourth bridge connection end. The third bridge connection end andthe fourth bridge connection end are exposed by the second bridgeinsulating layer. When the bridge sub-circuit board is installed on themain body sub-circuit board, the second side is closer to the main bodysub-circuit board than the first side.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardfurther includes a second bridge wiring layer at a second side of thesecond substrate opposite to the first side thereof, and a second bridgeinsulating layer laminated on a side of the second bridge wiring layerfar away from the second substrate. The first bridge wiring layerfurther includes the third bridge connection end, which is exposed bythe first bridge insulating layer. The second bridge wiring layerincludes the third wiring portion and the fourth bridge connection end,and the fourth bridge connection end is exposed by the second bridgeinsulating layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the bridge sub-circuit boardfurther includes a shielding layer at the second side of the secondsubstrate and laminated on the side of the second bridge insulatinglayer far away from the second substrate.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the third bridge connection endand the fourth bridge connection end of the bridge sub-circuit board arerespectively connected to the first bridge connection end and the secondbridge connection end of the main body sub-circuit board throughanisotropic conductive adhesives, soldering materials or connectors.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, surfaces of the first bridgeconnection end and the second bridge connection end include tinmaterials. The third bridge connection end and the fourth bridgeconnection end of the bridge sub-circuit board are respectively weldedto the first bridge connection end and the second bridge connection endof the main body sub-circuit board by the tin materials such that thebridge sub-circuit board is electrically connected to the main bodysub-circuit board.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardincludes a plurality of first bridge connection ends and a plurality ofsecond bridge connection ends. The bridge sub-circuit board may be inplural. A plurality of the bridge sub-circuit boards are installed onthe main body sub-circuit board by respectively electrically connectinga plurality of the third bridge connection ends and a plurality of thefourth bridge connection ends to a plurality of the first bridgeconnection ends and a plurality of the second bridge connection ends.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardfurther includes a terminal with a plurality of first contact padsthereon; an end of each of a plurality of wirings of the second wiringportion is electrically connected to each of some of the first contactpads in the terminal in one-to-one correspondence; an end of each of aplurality of wirings of the second functional wiring is electricallyconnected to each of some other of the first contact pads in theterminal in one-to-one correspondence; an end of each of a plurality ofwirings of the third functional wiring is electrically connected to eachof some further of the first contact pads in the terminal in one-to-onecorrespondence; some of the first contact pads respectively electricallyconnected to the second wiring portion, the third functional wiring andthe second functional wiring are spaced apart in the terminal.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the terminal includes a structureon the second main body wiring layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the terminal is disposed in awiring area of the main body sub-circuit board, and a transparency ofthe wiring area is higher than that of at least a part of an areaoutside the wiring area.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the wiring area only has a wiringlayer and a part of an insulating layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the wiring area does not have ashielding layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the main body sub-circuit boardfurther includes a terminal with a plurality of first contact pads; anend of each of a plurality of wirings of the second wiring portion iselectrically connected to each of some of the first contact pads in theterminal in one-to-one correspondence; an end of each of a plurality ofwirings of the second functional wiring is electrically connected toeach of some other of the first contact pads in the terminal inone-to-one correspondence; an end of each of a plurality of wirings ofthe third functional wiring is electrically connected to each of somefurther of the first contact pads in the terminal in one-to-onecorrespondence; some of the first contact pads electrically connected tothe second wiring portion, the third functional wiring and the secondfunctional wiring are continuously arranged in the terminal.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the terminal includes a structureon the second main body wiring layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the terminal is disposed in awiring area of the main body sub-circuit board, and a transparency ofthe wiring area is higher than that of at least a part of an areaoutside the wiring area.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the wiring area only has a wiringlayer and a part of an insulating layer.

For example, in the flexible circuit board provided by at least oneembodiment of the present disclosure, the wiring area does not have ashielding layer.

At least one embodiment of the present disclosure provides a flexiblecircuit board. The flexible circuit board includes: a main bodysub-circuit board including a first substrate, and a first bridgeconnection end, a second bridge connection end, a first wiring portionand a second wiring portion on the first substrate, in which the firstwiring portion and the second wiring portion are separated from eachother and electrically connected to the first bridge connection end andthe second bridge connection end, respectively; a bridge sub-circuitboard including a second substrate, and a third bridge connection end, afourth bridge connection end and a third wiring portion for a firstfunctional wiring on the second substrate, in which the third bridgeconnection end and the fourth bridge connection end are electricallyconnected by the third wiring portion, the bridge sub-circuit board isconfigured to be installed on the main body sub-circuit board byrespectively electrically connecting the third bridge connection end andthe fourth bridge connection end to the first bridge connection end andthe second bridge connection end, so that the first wiring portion, thethird wiring portion and the second wiring portion are sequentiallyelectrically connected to obtain the first functional wiring. An outlineshape of the first substrate is different from that of the secondsubstrate. The main body sub-circuit board includes a first main bodywiring layer at a first side of the first substrate and a first mainbody insulating layer laminated on a side of the first main body wiringlayer far away from the first substrate, the first side is a side of themain body sub-circuit board close to the bridge sub-circuit board. Themain body sub-circuit board further includes a second main body wiringlayer at a second side of the first substrate and a second main bodyinsulating layer laminated on a side of the second main body wiringlayer far away from the first substrate. A part of the first wiringportion is in the first main body wiring layer, and another part of thefirst wiring portion is in the second main body wiring layer. A part ofthe second wiring portion is in the first main body wiring layer, andanother part of the second wiring portion is in the second main bodywiring layer. The second functional wiring is all in the first main bodywiring layer, and the third functional wiring is all in the second mainbody wiring layer. The first main body insulating layer has a first viahole exposing the first bridge connection end and the second bridgeconnection end. At least some of the wirings of the first wiring portionin the second main body wiring layer are electrically connected to thefirst main body wiring layer through the second via hole forelectrically connecting to the bridge sub-circuit board through thefirst bridge connection end. At least some of the wirings of the secondwiring portion in the second main body wiring layer are electricallyconnected to the first main body wiring layer through the second viahole for electrically connecting to the bridge sub-circuit board throughthe second bridge connection end. The bridge sub-circuit board includesa first bridge wiring layer at a first side of the second substrate anda first bridge insulating layer laminated on a side of the first bridgewiring layer far away from the second substrate, in which the firstbridge wiring layer includes the third wiring portion. The bridgesub-circuit board further includes a ground layer at a second side ofthe second substrate opposite to the first side thereof. When the bridgesub-circuit board is installed on the main body sub-circuit board, thesecond side is closer to the main body sub-circuit board than the firstside. The bridge sub-circuit board further includes a second bridgeinsulating layer laminated on a side of the ground layer far away fromthe second substrate, and the second bridge insulating layer is providedwith a plurality of openings exposing a part of the ground layer, andthe plurality of openings serve as the third bridge connection endand/or the fourth bridge connection end for electrically connecting thebridge sub-circuit board to the main body sub-circuit board.

At least one embodiment of the disclosure provides a display device. Thedisplay device includes a display panel and a flexible circuit board.The display panel is provided with pixel units arranged in an array anda touch driving wiring, a touch sensing wiring. The display panelfurther includes a second functional circuit structure which is adisplay circuit structure and is electrically connected to the pixelunits. Second contact pads for electrically connecting to the flexiblecircuit board is also provided at a side of the display panel, some ofthe second contact pad are electrically connected to the secondfunctional circuit, some other of the second contact pads areelectrically connected to the touch driving wiring, and some further ofthe second contact pads are electrically connected to the touch sensingwiring. The some of the second contact pads electrically connected tothe second functional circuit structure are between the some other ofthe second contact pads electrically connected to the touch drivingwiring and the some further of the second contact pads electricallyconnected to the touch sensing wiring. The flexible circuit boardincludes a main body sub-circuit board and a bridge sub-circuit board.The main body sub-circuit board includes a first substrate, and a firstbridge connection end, a second bridge connection end, a first wiringportion and a second wiring portion on the first substrate. The firstwiring portion and the second wiring portion are separated from eachother and respectively electrically connected to the first bridgeconnection end and the second bridge connection end. The bridgesub-circuit board includes a second substrate, and a third bridgeconnection end, a fourth bridge connection end and a third wiringportion for a first functional wiring on the second substrate. The thirdbridge connection end and the fourth bridge connection end areelectrically connected by the third wiring portion. The bridgesub-circuit board is configured to be installed on the main bodysub-circuit board by respectively electrically connecting the thirdbridge connection end and the fourth bridge connection end to the firstbridge connection end and the second bridge connection end, so that thefirst wiring portion, the third wiring portion and the second wiringportion are sequentially electrically connected to obtain the firstfunctional wiring. An outline shape of the first substrate is differentfrom that of the second substrate. A terminal for electricallyconnecting to the display panel is also provided at a side of the mainbody sub-circuit board, and has a plurality of first contact pads. Themain body sub-circuit board further includes a second functional wiringand a third functional wiring. The third functional wiring is betweenthe first wiring portion and the second wiring portion. An orthographicprojection of the third functional wiring on the first substrate atleast partially overlaps with an orthographic projection of the bridgesub-circuit board on the first substrate. The first functional wiring ofthe main body sub-circuit board is electrically connected to the touchdriving wiring of the display panel, and the second functional wiring ofthe main body sub-circuit board is electrically connected to the touchsensing wiring of the display panel, or the first functional wiring ofthe main body sub-circuit board is electrically connected to the touchsensing wiring of the display panel, and the second functional wiring ofthe main body sub-circuit board is electrically connected to the touchdriving wiring of the display panel. The third functional wiring of themain body sub-circuit board is electrically connected to the secondfunctional circuit structure of the display panel. The flexible circuitboard further includes a first control circuit combination structureelectrically connected to the first functional wiring, and alsoelectrically connected to the second functional wiring. The touchdriving wiring of the display panel is electrically connected to thefirst control circuit combination structure of the flexible circuitboard through the first functional wiring, and the touch sensing wiringof the display panel is electrically connected to the first controlcircuit combination structure through the second functional wiring ofthe flexible circuit board; or the touch sensing wiring of the displaypanel is electrically connected to the first control circuit combinationstructure of the flexible circuit board through the first functionalwiring, and the touch driving wiring of the display panel iselectrically connected to the first control circuit combinationstructure through the second functional wiring of the flexible circuitboard. The second contact pads of the display panel are electricallyconnected to the first contact pads of the flexible circuit board.

For example, in the display device provided by at least one embodimentof the present disclosure, the first control circuit combinationstructure is configured to provide a first electrical signal to thefirst functional wiring or receive a first electrical signal from thefirst functional wiring. The first control circuit combination structureis used to install a first control circuit, which is a touch driving ICchip.

For example, in the display device provided by at least one embodimentof the present disclosure, the first control circuit combinationstructure is further configured to provide a second electrical signal tothe second functional wiring or receive a second electrical signal fromthe second functional wiring.

For example, in the display device provided by at least one embodimentof the present disclosure, the touch sensing wiring at least includes apart at a side of the display panel opposite to the second contact pads,and the touch driving wiring at least includes a part at any side exceptthe two sides mentioned above.

For example, in the display device provided by at least one embodimentof the present disclosure, the first functional wiring electricallyconnected to the touch driving wiring is bridged by the bridgesub-circuit board, a distance between the touch driving wiring and thefirst control circuit combination structure is greater than a distancebetween the touch sensing wiring and the first control circuitcombination structure, or alternatively, the first functional wiringelectrically connected to the touch sensing wiring is bridged by thebridge sub-circuit board, the distance between the touch sensing wiringand the first control circuit combination structure is greater than thedistance between the touch driving wiring and the first control circuitcombination structure.

For example, in the display device provided by at least one embodimentof the present disclosure, the first control circuit combinationstructure is disposed on the main body sub-circuit board andelectrically connected to the first wiring portion, or alternatively,the first control circuit combination structure is disposed on thebridge sub-circuit board and electrically connected to the third wiringportion. The first control circuit combination structure is configuredto provide a first electrical signal to the first functional wiring orreceive a first electrical signal from the first functional wiring.

For example, in the display device provided by at least one embodimentof the present disclosure, the main body sub-circuit board includes afirst main body wiring layer at a first side of the first substrate anda first main body insulating layer laminated on a side of the first mainbody wiring layer far away from the first substrate, the first side is aside of the main body sub-circuit board near the bridge sub-circuitboard. The main body sub-circuit board further includes a second mainbody wiring layer at a second side of the first substrate and a secondmain body insulating layer laminated on a side of the second main bodywiring layer far away from the first substrate. A part of the firstwiring portion is in the first main body wiring layer and another partof the first wiring portion is in the second main body wiring layer. Apart of the second wiring portion is in the first main body wiringlayer, and another part of the second wiring portion is in the secondmain body wiring layer.

For example, in the display device provided by at least one embodimentof the present disclosure, a part of the second functional wiring is inthe first main body wiring layer, and another part of the secondfunctional wiring is in the second main body wiring layer, oralternatively, the second functional wiring is all in the first mainbody wiring layer. A part of the third functional wiring is in the firstmain body wiring layer, and another part of the third functional wiringis in the second main body wiring layer, or the third functional wiringis all in the second main body wiring layer.

For example, in the display device provided by at least one embodimentof the present disclosure, the second functional wiring is all in thefirst main body wiring layer, and the third functional wiring is all inthe second main body wiring layer.

For example, in the display device provided by at least one embodimentof the present disclosure, the first main body insulating layer has afirst via hole exposing the first bridge connection end and the secondbridge connection end.

For example, in the display device provided by at least one embodimentof the present disclosure, at least a part of a wiring of the firstwiring portion on the second main body wiring layer is electricallyconnected to the first main body wiring layer through a second via hole,for electrically connecting to the bridge sub-circuit board through thefirst bridge connection end; and at least a part of a wiring of thesecond wiring portion on the second main body wiring layer iselectrically connected to the first main body wiring layer through thesecond via hole, for electrically connecting to the bridge sub-circuitboard through the second bridge connection end.

For example, in the display device provided by at least one embodimentof the present disclosure, the bridge sub-circuit board includes a firstbridge wiring layer at a first side of the second substrate and a firstbridge insulating layer laminated on a side of the first bridge wiringlayer far away from the second substrate, the first bridge wiring layerincludes the third wiring portion.

For example, in the display device provided by at least one embodimentof the present disclosure, the bridge sub-circuit board further includesa ground layer at a second side of the second substrate opposite to thefirst side. When the bridge sub-circuit board is installed on the mainbody sub-circuit board, the second side is closer to the main bodysub-circuit board than the first side.

For example, in the display device provided by at least one embodimentof the present disclosure, the bridge sub-circuit board further includesa second bridge insulating layer laminated on a side of the ground layerfar away from the second substrate. The second bridge insulating layerhas a plurality of openings exposing a part of the ground layer, and theplurality of openings serve as the third bridge connection end and/orthe fourth bridge connection end for electrically connecting the bridgesub-circuit board to the main body sub-circuit board.

For example, in the display device provided by at least one embodimentof the present disclosure, the bridge sub-circuit board further includesa shielding layer at the second side of the second substrate, and theshielding layer is laminated on a side of the ground layer far away fromthe second electrode plate.

For example, in the display device provided by at least one embodimentof the present disclosure, the third bridge connection end and thefourth bridge connection end of the bridge sub-circuit board arerespectively connected to the first bridge connection end and the secondbridge connection end of the main body sub-circuit board throughanisotropic conductive adhesives, soldering materials or connectors.

For example, in the display device provided by at least one embodimentof the present disclosure, surfaces of the first bridge connection endand the second bridge connection end include tin materials. The thirdbridge connection end and the fourth bridge connection end of the bridgesub-circuit board are respectively welded to the first bridge connectionend and the second bridge connection end of the main body sub-circuitboard by tin materials to electrically connect the bridge sub-circuitboard to the main body sub-circuit board.

For example, in the display device provided by at least one embodimentof the present disclosure, the main body sub-circuit board includes aplurality of first bridge connection ends and a plurality of secondbridge connection ends. The bridge sub-circuit board may be provided asplural, and a plurality of the bridge sub-circuit boards are installedon the main body sub-circuit board by respectively electricallyconnecting to the plurality of first bridge connection ends and theplurality of second bridge connection ends through the plurality ofthird bridge connection ends and the plurality of fourth bridgeconnection ends.

For example, in the display device provided by at least one embodimentof the present disclosure, the main body sub-circuit board furtherincludes a terminal with a plurality of first contact pads thereon; anend of each of a plurality of wirings of the second wiring portion iselectrically connected to each of some of the first contact pads in theterminal in one-to-one correspondence; an end of each of a plurality ofwirings of the second functional wiring is electrically connected toeach of some other of the first contact pads in the terminal inone-to-one correspondence; an end of each of a plurality of wirings ofthe third functional wiring is electrically connected to each of somefurther of the first contact pads in the terminal in one-to-onecorrespondence; some of the first contact pads respectively electricallyconnected to the second wiring portion, the third functional wiring andthe second functional wiring are spaced apart in the terminal.

For example, in the display device provided by at least one embodimentof the present disclosure, the terminal includes a structure on thesecond main body wiring layer.

For example, in the display device provided by at least one embodimentof the present disclosure, the terminal is disposed in a wiring area ofthe main body sub-circuit board, a transparency of the wiring area ishigher than that of at least a part of an area outside the wiring area.

For example, in the display device provided by at least one embodimentof the present disclosure, the wiring area only has a wiring layer and apart of an insulating layer.

For example, in the display device provided by at least one embodimentof the present disclosure, the wiring area does not have a shieldinglayer.

For example, in the display device provided by at least one embodimentof the present disclosure, the main body sub-circuit board furtherincludes a terminal with a plurality of first contact pads; an end of aplurality of wirings of the second wiring portion is electricallyconnected to each of some of the first contact pads in the terminal inone-to-one correspondence; an end of a plurality of wirings of thesecond functional wiring is electrically connected to each of some otherof the first contact pads in the terminal in one-to-one correspondence;an end of a plurality of wirings of the third functional wiring iselectrically connected to each of some further of the first contact padsin the terminal in one-to-one correspondence; some of the first contactpads electrically connected to the second wiring portion, the thirdfunctional wiring and the second functional wiring are continuouslyarranged in the terminal.

For example, in the display device provided by at least one embodimentof the present disclosure, the terminal includes a structure on thesecond main body wiring layer.

For example, in the display device provided by at least one embodimentof the present disclosure, the terminal is disposed in a wiring area ofthe main body sub-circuit board, a transparency of the wiring area ishigher than that of at least a part of an area outside the wiring area.

For example, in the display device provided by at least one embodimentof the present disclosure, the wiring area only has a wiring layer and apart of an insulating layer.

For example, in the display device provided by at least one embodimentof the present disclosure, the wiring area does not have a shieldinglayer.

For example, in the display device provided by at least one embodimentof the present disclosure, the display device further includes a secondcontrol circuit combination structure.

For example, in the display device provided by at least one embodimentof the present disclosure, the second control circuit is configured toprovide a third electrical signal to the third functional wiring orreceive a third electrical signal from the third functional wiring.

For example, in the display device provided by at least one embodimentof the present disclosure, the second control circuit combinationstructure is configured to install a second control circuit, and thesecond control circuit is a driving IC chip.

For example, in the display device provided by at least one embodimentof the present disclosure, the bridge sub-circuit board is connected tothe third functional wiring, the first wiring portion and the secondwiring portion pass under the bridge sub-circuit board for connection.

At least one embodiment of the present disclosure provides a displaydevice including a display panel and a flexible circuit board. Thedisplay panel is provided with pixel units arranged in an array, a touchdriving wiring and a touch sensing wiring. The display panel furtherincludes a second functional circuit structure which is a displaycircuit structure and is electrically connected to the pixel units.Second contact pads for electrically connecting to the flexible circuitboard are provided on a side of the display panel. Some of the secondcontact pads are electrically connected to the second functionalcircuit, some other of the second contact pads are electricallyconnected to the touch driving wiring, and some further of the secondcontact pads are electrically connected to the touch sensing wiring. Thesome of the second contact pads electrically connected to the secondfunctional circuit structure are between the some other of the secondcontact pads electrically connected to the touch driving wiring and thesome further of the second contact pads electrically connected to thetouch sensing wiring. The flexible circuit board includes a main bodysub-circuit board and a bridge sub-circuit board. The main bodysub-circuit board includes a first substrate, and a first bridgeconnection end, a second bridge connection end, a first wiring portionand a second wiring portion on the first substrate. The first wiringportion and the second wiring portion are separated from each other andelectrically connected to the first bridge connection end and the secondbridge connection end, respectively. The bridge sub-circuit boardincludes a second substrate, and a third bridge connection end, a fourthbridge connection end and a third wiring portion for first functionalwiring on the second substrate. The third bridge connection end and thefourth bridge connection end are electrically connected by the thirdwiring portion. The bridge sub-circuit board is configured to beinstalled on the main body sub-circuit board by respectivelyelectrically connecting the third bridge connection end and the fourthbridge connection end to the first bridge connection end and the secondbridge connection end, so that the first wiring portion, the thirdwiring portion and the second wiring portion are sequentiallyelectrically connected to obtain the first functional wiring. An outlineshape of the first substrate is different from that of the secondsubstrate. The main body sub-circuit board includes a first main bodywiring layer at a first side of the first substrate and a first mainbody insulating layer laminated on a side of the first main body wiringlayer far away from the first substrate, the first side is a side of themain body sub-circuit board close to the bridge sub-circuit board. Themain body sub-circuit board also includes a second main body wiringlayer at a second side of the first substrate and a second main bodyinsulating layer laminated on a side of the second main body wiringlayer far away from the first substrate. A part of the first wiringportion is in the first main body wiring layer, and another part of thefirst wiring portion is in the second main body wiring layer. A part ofthe second wiring portion is in the first main body wiring layer, andanother part is in the second main body wiring layer. The secondfunctional wiring is all in the first main body wiring layer, and thethird functional wiring is all in the second main body wiring layer. Thefirst main body insulating layer has a first via hole exposing the firstbridge connection end and the second bridge connection end. At least apart of a wiring of the first wiring portion on the second main bodywiring layer is electrically connected to the first main body wiringlayer through a second via hole for electrically connecting to thebridge sub-circuit board through the first bridge connection end, and atleast a part of a wiring of the second wiring portion on the second mainbody wiring layer is electrically connected to the first main bodywiring layer through the second via hole for electrically connecting tothe bridge sub-circuit board through the second bridge connection end.The first main body wiring layer includes the first wiring portion, thesecond wiring portion, the first bridge connection end and the secondbridge connection end. The first bridge connection end and the secondbridge connection end are exposed by the first main body insulatinglayer. The main body sub-circuit board also includes a second main bodywiring layer at a second side of the first substrate opposite to thefirst side, and a second main body insulating layer laminated on a sideof the second main body wiring layer far away from the first substrate.The second main body wiring layer includes the first wiring portion andthe second wiring portion. The bridge sub-circuit board includes a firstbridge wiring layer at a first side of the second substrate and a firstbridge insulating layer laminated on a side of the first bridge wiringlayer far away from the second substrate. The first bridge wiring layerincludes the third wiring portion. The bridge sub-circuit board alsoincludes a ground layer at a second side of the second substrateopposite to the first side thereof. When the bridge sub-circuit board isinstalled on the main body sub-circuit board, the second side is closerto the main body sub-circuit board than the first side. The bridgesub-circuit board also includes a second bridge insulating layerlaminated on a side of the ground layer far away from the secondsubstrate. The second bridge insulating layer is provided with aplurality of openings exposing part of the ground layer, and theplurality of openings serve as the third bridge connection end and/orthe fourth bridge connection end for electrically connecting the bridgesub-circuit board to the main body sub-circuit board. A terminal forelectrically connecting to the display panel is also provided at a sideof the main body sub-circuit board, and has a plurality of first contactpads. The main body sub-circuit board also includes a second functionalwiring and a third functional wiring. The third functional wiring isbetween the first wiring portion and the second wiring portion. Anorthographic projection of the third functional wiring on the firstsubstrate at least partially overlaps with an orthographic projection ofthe bridge sub-circuit board on the first substrate. The firstfunctional wiring of the main body sub-circuit board is electricallyconnected to the touch driving wiring of the display panel. The secondfunctional wiring of the main body sub-circuit board is electricallyconnected to the touch sensing wiring of the display panel. The thirdfunctional wiring of the main body sub-circuit board is electricallyconnected to a second functional circuit structure of the display panel.The flexible circuit board also includes a first control circuitcombination structure. The first control circuit combination structureis electrically connected to the first functional wiring, and alsoelectrically connected to the second functional wiring. The touchdriving wiring of the display panel is electrically connected to thefirst control circuit combination structure of the flexible circuitboard through the first functional wiring. The touch sensing wiring ofthe display panel is electrically connected to the first control circuitcombination structure through the second functional wiring of theflexible circuit board, and the second contact pads of the display paneland the first contact pads of the flexible circuit board areelectrically connected.

For example, in the display device provided by at least one embodimentof the present disclosure, the bridge sub-circuit board is connected tothe third functional wiring, and the first wiring portion and the secondwiring portion pass under the bridge sub-circuit board for connection.

At least one embodiment of the disclosure provides a manufacturingmethod of a flexible circuit board. The manufacturing method includes:providing a main body sub-circuit board, in which the main bodysub-circuit board includes a first substrate, and a first bridgeconnection end, a second bridge connection end, a first wiring portionand a second wiring portion on the first substrate, the first wiringportion and the second wiring portion are separated from each other andrespectively electrically connected to the first bridge connection endand the second bridge connection end; providing a bridge sub-circuitboard, in which the bridge sub-circuit board includes a secondsubstrate, and a third bridge connection end, a fourth bridge connectionend and a third wiring portion for a first functional wiring on thesecond substrate, the third bridge connection end and the fourth bridgeconnection end are electrically connected by the third wiring portion,electrically connecting the third bridge connection end and the fourthbridge connection end of the bridge sub-circuit board respectively tothe first bridge connection end and the second bridge connection end ofthe main body sub-circuit board, so that the bridge sub-circuit board isinstalled on the main body sub-circuit board; and the first substrate isnot in direct contact with the second substrate.

For example, in the manufacturing method provided by at least oneembodiment of the present disclosure, the third bridge connection endand the fourth bridge connection end of the bridge sub-circuit board arerespectively connected to the first bridge connection end and the secondbridge connection end of the main body sub-circuit board by hotpressing, welding or connectors.

At least one embodiment of the present disclosure provides a circuitboard structure including a main circuit board, a transfer circuitboard, and a connector. The main circuit board has a double circuitlayer structure and carries the main board lapping end. The transfercircuit board has a double circuit layer structure, laminated on themain circuit board and carries a first element lapping end for lapping afirst element set, a first leading wire set connected to the firstelement lapping end, and a transfer board lapping end connected to thefirst leading wire set. The connector is disposed between the maincircuit board and the transfer circuit board for connecting the mainboard lapping end and the transfer board lapping end.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, the circuit board structurefurther includes a shielding layer which is laminated between the maincircuit board and the transfer circuit board.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, the main circuit board furthercarries a second leading wire set. An orthographic projection of thetransfer circuit board on the main circuit board at least covers a partof the second leading wire set.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, the main circuit board furthercarries a first group of external pins. A part of the first group ofexternal pins are connected to the main board lapping end to connect thepart of the first leading wire set, and a part of the first group ofexternal pins are connected to the second leading wire set.

For example, in the circuit board structure provided by at least oneembodiment of this disclosure, the main board lapping end includes aplurality of main sub-board lapping ends, the transfer board lapping endincludes a plurality of transfer sub-board lapping ends, and theconnector is in plural. The main sub-board lapping ends are connected tothe lapping sub-board lapping ends through a plurality of the connectorsin one-to-one correspondence.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, the number of the main sub-boardlapping ends is two, and these two main sub-board lapping ends arerespectively arranged at opposite sides of the second leading wire set.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, the main circuit board furthercarries a second group of external pins; a part of the second externalpin set is connected to the second leading wire set, and a part of thesecond external pin set is connected to the main board lapping end toconnect a part of the first leading wire set.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, at least one of the main circuitboard and the transfer circuit board is a flexible circuit board.

For example, in the circuit board structure provided by at least oneembodiment of the present disclosure, the main circuit board includes afirst substrate, and a circuit layer at a side of the first substrate orcircuit layers at two sides of the first substrate. The transfer circuitboard includes a second substrate, and a circuit layer at a side of thesecond substrate or circuit layers at two sides of the second substrate.

At least one embodiment of the present disclosure provides a displaypanel including the above-mentioned circuit board structure.

The present disclosure provides a circuit board structure and a displaypanel thereof. The circuit board structure includes a main circuitboard, a transfer circuit board and a connector. The main circuit boardhas a double circuit layer structure and carries a main board lappingend. The transfer circuit board has a double circuit layer structurelaminated on the main circuit board and carries a first element lappingend for lapping a first element set, a first leading wire set connectedto the first element lapping end, and a transfer board lapping endconnected to the first leading wire set. A connector is arranged betweenthe main circuit board and the transfer circuit board, for connectingthe main board lapping end and the transfer board lapping end. In thecircuit board structure provided by the present disclosure, two circuitlayers may be provided on the main circuit board and the transfercircuit board. On the one hand, the circuit board structure provided bythe present disclosure can reduce the occupied space of the circuitboard structure by a laminated arrangement of the double circuit layercircuit board; and on the other hand, the double circuit layer circuitboard has mature manufacturing process and simple structural design, soas to reduce the design cost of the circuit board.

It should be understood that the above general description and thefollowing detailed description are only exemplary and explanatory, anddo not limit the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A brief introduction will be made below to the accompanying drawingsrequired for the description of embodiments or the prior art, in orderto illustrate technical solutions in embodiments of the presentdisclosure or in the prior art more clearly. Apparently, the drawings inthe following description are only some embodiments of the presentdisclosure, but do not limit this disclosure. The accompanying drawings,which are incorporated in and constitute a part of this specification,illustrate embodiments consistent with the present disclosure andtogether with the description, serve to explain the principles of thepresent disclosure. It is apparent that the accompanying drawings in thefollowing description are only some of the embodiments of the presentdisclosure, and other drawings may be obtained from these accompanyingdrawings by those skilled in the art without any creative work.

FIG. 1A is a schematic plan view of a flexible circuit board provided byat least one embodiment of the present disclosure;

FIG. 1B is a schematic plan view of a flexible circuit board provided byat least one embodiment of the present disclosure;

FIG. 1C is a schematic plan view of a flexible circuit board provided byat least one embodiment of the present disclosure;

FIG. 1D is a schematic plan view of a flexible circuit board provided byat least one embodiment of the present disclosure;

FIG. 2 is a schematic plan view of a main body sub-circuit board of aflexible circuit board provided by at least one embodiment of thepresent disclosure;

FIG. 3 is a schematic plan view of a bridge sub-circuit board of aflexible circuit board provided by at least one embodiment of thepresent disclosure;

FIG. 4A is a schematic plan view of a main body sub-circuit board of aflexible circuit board provided by at least one embodiment of thepresent disclosure;

FIG. 4B is a schematic plan view of a bridge sub-circuit board of aflexible circuit board provided by at least one embodiment of thepresent disclosure;

FIG. 5A is a schematic plan view of a main body sub-circuit board of aflexible circuit board provided by at least one embodiment of thepresent disclosure;

FIG. 5B is a schematic plan view of a main body sub-circuit board of aflexible circuit board provided by at least one embodiment of thepresent disclosure;

FIG. 6A is a schematic cross-sectional view of a main body sub-circuitboard of a flexible circuit board provided by at least one embodiment ofthe present disclosure;

FIG. 6B is a schematic cross-sectional view of a main body sub-circuitboard of a flexible circuit board provided by at least one embodiment ofthe present disclosure;

FIG. 7A is another schematic cross-sectional view of a main bodysub-circuit board of a flexible circuit board provided by at least oneembodiment of the present disclosure;

FIG. 7B is another schematic cross-sectional view of a main bodysub-circuit board of a flexible circuit board provided by at least oneembodiment of the present disclosure;

FIG. 8A is a schematic cross-sectional view of a bridge sub-circuitboard of a flexible circuit board provided by at least one embodiment ofthe present disclosure;

FIG. 8B is a schematic cross-sectional view of a bridge sub-circuitboard of a flexible circuit board provided by at least one embodiment ofthe present disclosure;

FIG. 8C is a schematic cross-sectional view of a bridge sub-circuitboard of a flexible circuit board provided by at least one embodiment ofthe present disclosure;

FIG. 8D is a schematic cross-sectional view of a bridge sub-circuitboard of a flexible circuit board provided by at least one embodiment ofthe present disclosure;

FIG. 9A is another schematic cross-sectional view of a bridgesub-circuit board of a flexible circuit board provided by at least oneembodiment of the present disclosure;

FIG. 9B is another schematic cross-sectional view of a bridgesub-circuit board of a flexible circuit board provided by at least oneembodiment of the present disclosure;

FIG. 10A is a schematic view of an electronic device module provided byat least one embodiment of the present disclosure;

FIG. 10B is a schematic view of another electronic device moduleprovided by at least one embodiment of the present disclosure;

FIG. 11 is a schematic view of a display device provided by someembodiments of the present disclosure;

FIG. 12 is a manufacturing flow chart of a flexible circuit boardprovided by some embodiments of the present disclosure;

FIG. 13 is a schematic structural view of a main circuit board in anexemplary embodiment of the circuit board structure of the presentdisclosure;

FIG. 14 is a schematic structural view of a transfer circuit board in anexemplary embodiment of the circuit board structure of the presentdisclosure;

FIG. 15 is a schematic structural view of an exemplary embodiment of thecircuit board structure of the present disclosure;

FIG. 16 is a schematic structural view of another exemplary embodimentof the circuit board structure of the present disclosure;

FIG. 17 is a schematic structural view of an exemplary embodiment of thecircuit board structure of the present disclosure;

FIG. 18 is a schematic structural view of a main circuit board in anexemplary embodiment of the circuit board structure of the presentdisclosure;

FIG. 19 is a schematic structural view of a transfer circuit board in anexemplary embodiment of the circuit board structure of the presentdisclosure; and

FIG. 20 is a schematic structural view of an exemplary embodiment of thecircuit board structure of the present disclosure.

DETAILED DESCRIPTION

In order to make objects, technical solutions and advantages of theembodiments of the present disclosure more apparent, the technicalsolutions of the embodiments of the present disclosure will be describedclearly and completely in combination with the accompanying drawings ofthe embodiments of the present disclosure. Obviously, the describedembodiments are merely a part of the embodiments, but not all of theembodiments of the present disclosure. Based on the describedembodiments of this disclosure, Other embodiments obtained by the personskilled in the art without any creative effort are within the scope ofthe present disclosure.

Unless otherwise defined, technical terms or scientific terms used inthis disclosure should be general meanings as comprehended by the personwith ordinary skill in the art of the present disclosure. The “first”,“second” and similar words used in the present disclosure do not referto any order, number, or importance, but only used to distinguish thedifferent components. The “include” or comprise” and similar words referto the elements or articles prior to the word and encompass the elementsor articles and their equivalents posterior to the word, and otherelements or articles are included. The word “connect” and the like arenot limited to physical or mechanical connection, but may includeelectrical connection, no matter whether direct or indirect.

Now, the exemplary embodiments will be described more fully withreference to the accompanying drawings. However, the exemplaryembodiments can be embodied in a variety of forms and should not beconstrued as limiting the embodiments set forth herein. Instead, theseembodiments are provided so that the present disclosure will be thoroughand complete, and the concepts of the exemplary embodiments will befully given to those skilled in the art. Same reference numbers denotethe same or similar structures in the figures, and thus the detaileddescription thereof will be omitted.

Although relative terms such as “above” and “under” are used herein todescribe the relationship of one component relative to anothercomponent, such terms are used herein only for the sake of convenience,for example, in the direction shown in the figure, it should beunderstood that if the referenced device is inversed upside down, acomponent described as “above” will become a component described as“under”. Other relative terms, such as “high”, “low”, “top”, “bottom”,“left” and “right” have similar meanings. When a structure is describedas “above” another structure, it probably means that the structure isintegrally formed on another structure, or, the structure is “directly”disposed on another structure, or the structure is “indirectly” disposedon another structure through an additional structure.

Various signal wirings may be generally integrated in the flexiblecircuit board for transmitting different types of signals. When thereare many types of signal wirings on the flexible circuit board, such asvarious types of signal wirings for display signals, touch signals,fingerprint identification signals, or the like, the difficulty ofwiring in the flexible circuit board will be increased. Therefore, theflexible circuit board is usually formed to have multiple wiring layers,for example, four or six wiring layers, so as to provide convenience forthe arrangement of various types of wirings, so that various types ofwirings may be distributed on different layers to reduce the mutualinterference between different types of wirings. However, in a processof manufacturing a flexible circuit board with multiple wiring layers,it is necessary to form insulating layers (and corresponding adhesivelayers) between adjacent ones of the wiring layers, and if necessary, itis also necessary to form a shielding layer (an electromagnetic signal)between different wirings in order to avoid signal crosstalk betweendifferent wirings, which all increase the manufacturing difficulty ofthe flexible circuit board.

At least one embodiment of the present disclosure provides a flexiblecircuit board. The flexible circuit board includes a first substrate, aswell as a main body sub-circuit board and a bridge sub-circuit boardarranged on the first substrate. The main body sub-circuit boardincludes a first bridge connection end, a second bridge connection end,a first wiring portion and a second wiring portion. The first wiringportion and the second wiring portion are separated from each other andelectrically connected to the first bridge connection end and the secondbridge connection end, respectively. The bridge sub-circuit boardincludes a second substrate, as well as a third bridge connection end, afourth bridge connection end and a third wiring portion arranged on thesecond substrate. The third bridge connection end and the fourth bridgeconnection end are electrically connected by the third wiring portion,and the first substrate is not in direct contact with the secondsubstrate. The bridge sub-circuit board is configured to be installed onthe main body sub-circuit board by electrically connecting the thirdbridge connection end and the fourth bridge connection end to the firstbridge connection end and the second bridge connection end,respectively.

An electronic device module provided by at least one embodiment of thepresent disclosure includes an electronic device substrate and theabove-mentioned flexible circuit board. The electronic device substrateincludes a first functional circuit structure, and the first functionalwiring of the flexible circuit board is electrically connected to thefirst functional circuit structure.

At least one embodiment of the present disclosure provides a displaydevice including the above-mentioned electronic device module.

The flexible circuit board, the manufacturing method thereof, and thedisplay device of the present disclosure will be described in followingseveral specific embodiments.

Some embodiments of the present disclosure provide a flexible circuitboard, and FIG. 1A is a schematic plan view of the flexible circuitboard. As shown in FIG. 1A, the flexible circuit board 10 includes amain body sub-circuit board 100 and a bridge sub-circuit board 200 whichmay be electrically connected to the main body sub-circuit board 100.

FIG. 2 is a schematic plan view of the main body sub-circuit board 100.As shown in FIG. 2 , the main body sub-circuit board 100 includes afirst substrate, as well as a first bridge connection end 101, a secondbridge connection end 102, a first wiring portion 103 and a secondwiring portion 104 arranged on the first substrate. The first wiringportion 103 and the second wiring portion 104 are separated from eachother by a predetermined space (distance), and are electricallyconnected to the first bridge connection end 101 and the second bridgeconnection end 102, respectively. For example, the first bridgeconnection end 101 includes a plurality of first contact pads, and thesecond bridge connection end 102 includes a plurality of second contactpads. For example, the first wiring portion 103 includes a plurality ofwirings, an end of each of the wirings is electrically connected to eachof a plurality of first contact pads of the first bridge connection end101 in one-to-one correspondence. The second wiring portion 104 alsoincludes a plurality of wirings, and an end of each of the wirings iselectrically connected to each of a plurality of second contact pads offirst bridge connection end 102 in one-to-one correspondence. Twowirings of the first wiring portion 103 and two wirings of the secondwiring portion 104 are merely shown in the figure, the embodiments ofthe present disclosure are not limited thereto.

FIG. 3 is a schematic plan view of the bridge sub-circuit board 200. Asshown in FIG. 3 , the bridge sub-circuit board 200 includes a secondsubstrate, and a third bridge connection end 201, a fourth bridgeconnection end 202 and a third wiring portion 203 arranged on the secondsubstrate. The third bridge connection end 201 and the fourth bridgeconnection end 202 are electrically connected by the third wiringportion 203. For example, the third bridge connection end 201 includes aplurality of third contact pads, the fourth bridge connection end 202includes a plurality of fourth contact pads, and the third wiringportion 203 includes a plurality of wirings. These wirings areelectrically connected at ends thereof to a plurality of third contactpads of the third bridge connection end 201 in one-to-onecorrespondence, and are electrically connected at another ends thereofto a plurality of fourth contact pads of the fourth bridge connectionend 202 in one-to-one correspondence. Although only two wirings of thethird wiring portion 203 are shown in the figure, embodiments of thepresent disclosure are not limited thereto.

The bridge sub-circuit board 200 is configured to be installed on themain body sub-circuit board 100 by electrically connecting the thirdbridge connection end 201 and the fourth bridge connection end 202 tothe first bridge connection end 101 and the second bridge connection end102, respectively. When the bridge sub-circuit board 200 is installed onthe main body sub-circuit board 100, the first wiring portion 103, thethird wiring portion 203, and the second wiring portion 104 aresequentially electrically connected to obtain the first functionalwiring. Therefore, electrical signals may be transmitted from the firstwiring portion 103 to the second wiring portion 104 via the third wiringportion 203, or may be transmitted from the second wiring portion 104 tothe first wiring portion 103 via the third wiring portion 203.

In some embodiments, an outline shape of the bridge sub-circuit board200 is a symmetrical structure.

For example, FIG. 1A shows that a bridge sub-circuit board 200 isinstalled on a main body sub-circuit board 100 by engaging a thirdbridge connection end 201 and a fourth bridge connection end 202 with afirst bridge connection end 101 and a second bridge connection end 102,respectively. In some embodiments, the main body sub-circuit board 100and the bridge sub-circuit board 200 may also be in a state to beconnected, that is, the individual main body sub-circuit board 100 andbridge sub-circuit board 200 are also within the protection scope ofthis disclosure.

For example, in some embodiments, as shown in FIG. 2 , the flexiblecircuit board 10 may further include a first control circuit combinationstructure 105 disposed on the main body sub-circuit board 100. Forexample, the first control circuit combination structure 105 includes aplurality of contact pads for installing the first control circuit, anda part of the contact pads are electrically connected to another ends ofa plurality of wirings of the first wiring portion 103 in one-to-onecorrespondence. The first control circuit combination structure 105 isconfigured to provide a first electrical signal to the first functionalwiring or receive a first electrical signal from the first functionalwiring.

The first control circuit may be, for example, a driving IC chip. Thedriving IC chip with the flexible circuit board in many manners (i.e.,package manner), such as tape carrier package (TCP), chip on film (COF)package and the like. In the TCP manner, the flexible circuit boardincludes a plurality of contact pads; and a plurality of pins of thedriving IC chip are welded (for example, by eutectic welding) to aplurality of contact pads of the flexible circuit board in one-to-onecorrespondence, or are electrically connected in one-to-onecorrespondence by anisotropic conductive adhesives (ACF), and at leastthe welded part is protected by, for example, epoxy resin. In order toincrease the flexibility of flexible circuit board in the TCP mode, aslit may be formed in the packaged part. In the COF packaging mode, theflexible circuit board includes a plurality of contact pads; and aplurality of pins of the driving IC chip are directly pressure-molded ona plurality of contact pads of flexible circuit board through ACF, sothat the pins of driving IC chip are electrically connected to thecontact pads of flexible circuit board in one-to-one correspondence. Forexample, the size and arrangement of the contact pads on the flexiblecircuit board for bonding the driving IC chips may be adjusted accordingto different types of packaging methods or the driving IC chips to bepackaged, for example, these contact pads may be arranged in a longstrip or rectangular shape. The embodiment of the present disclosuredoes not limit the packaging mode of the driving IC chip.

For example, in some embodiments, as shown in FIG. 2 , the main bodysub-circuit board 100 of the flexible circuit board 10 may furtherinclude a second functional wiring 106 with a plurality of wirings. Someother of the contact pads in the first control circuit combinationstructure 105 are electrically connected to a plurality of wirings ofthe second functional wiring 106 in one-to-one correspondence. At thistime, the first control circuit installed on the first control circuitcombination structure 105 is also configured to provide a secondelectrical signal to the second functional wiring 106 or receive asecond electrical signal from the second functional wiring 106.

For example, in some embodiments, as shown in FIGS. 1A and 2 , the mainbody sub-circuit board 100 of the flexible circuit board 10 furtherincludes a third functional wiring 107 that is located between the firstwiring portion 103 and the second wiring portion 104, thereby passingthrough a predetermined space between the first wiring portion 103 andthe second wiring portion 104, for example, the third functional wiring107 intersects the bridge sub-circuit board 200 installed on the mainbody sub-circuit board 100 in a direction perpendicular to a boardsurface of the main body sub-circuit board 100. At this time, the thirdwiring portion 203 on the bridge sub-circuit board 200 across the thirdfunctional wiring 107 to electrically connect to the first wiringportion 103 and the second wiring portion 104 at both sides of the mainbody sub-circuit board 100, to avoid the intersected wirings fromforming on the main body sub-circuit board 100 itself, and further avoidor weaken the signal crosstalk between different wirings, or avoid theaddition of additional functional layers for preventing the signalcrosstalk, thus avoid the complexity of the circuit board structure. Inaddition, this design may simplify the wiring layout of the main bodysub-circuit board 100, and make the manufacturing process of main bodysub-circuit board simplified.

For example, in some embodiments, as shown in FIG. 2 , the first wiringportion 103, the second wiring portion 104, and the third functionalwiring 107 are wired in the same direction, such as in parallel orsubstantially in parallel (as long as the wirings are not intersected),for example parallel wirings in the vertical direction as shown in thefigures. Therefore, the above-mentioned wirings on the main bodysub-circuit board 100 have no intersecting parts, and the wiring layoutis simpler. For example, in some embodiments, these wirings may bearranged in the same wiring layer, to reduce the number of wiring layersand simplify a layered structure of the flexible circuit board.

For example, in some embodiments, as shown in FIGS. 1B and 2 , theflexible circuit board 10 may further include a second control circuitcombination structure 108 disposed on the main body sub-circuit board100. For example, the second control circuit combination structure 108includes a plurality of contact pads for installing the second controlcircuit, and at least some of the contact pads are electricallyconnected to the end of the third functional wiring 107 in one-to-onecorrespondence. The second control circuit combination structure 108 isconfigured to provide a third electrical signal to the third functionalwiring 107 or receive a third electrical signal from the thirdfunctional wiring 107. For example, the third functional wiring 107 isdivided into two parts, in which a first part of the third functionalwiring 107 is electrically connected to a first end (shown as a lowerend in the figure) of the second control circuit combination structure108, and a second part of the third functional wiring 107 iselectrically connected between a second end (shown as an upper end inthe figure) of the second control circuit bonding structure 108 and thecontact pad (as described below) formed on a side edge of the main bodysub-circuit board 100.

For example, the second control circuit may also be a driving IC chip.The first control circuit and the second control circuit arerespectively used for realizing different driving functions. Asmentioned above, the driving IC chip is combined with the flexiblecircuit board in a manner, such as, a tape carrier package (TCP), a chipon film (COF) package, or the like. For example, the second controlcircuit bonding structure 108 includes a plurality of contact pads forconnecting with the driving IC chip. Similarly, the size and arrangementof these contact pads may be adjusted according to different types ofpackaging methods or driving IC chips to be packaged, which is notspecifically limited by the embodiments of this disclosure.

For example, as shown in FIG. 4A and FIG. 4B, in some embodiments, thefirst control circuit combination structure 105 may also be formed onthe bridge sub-circuit board 200. At this time, on the main bodysub-circuit board 100, the first wiring portion 103 and the secondwiring portion 104 are electrically connected to the first bridgeconnection end 101 and the second bridge connection end 102,respectively; and on the bridge sub-circuit board 200, the third wiringportion 203 is divided into two parts, in which a first part of thethird wiring portion 203 is electrically connected between the firstcontrol circuit combination structure 105 and the third bridgeconnection end 201, and a second part of the third wiring portion 203 iselectrically connected between the first control circuit combinationstructure 105 and the fourth bridge connection end 202. Therefore, thefirst wiring portion 103 and the second wiring portion 104 on the mainbody sub-circuit board 100 are electrically connected to the firstcontrol circuit combination structure 105 on the bridge sub-circuitboard 200, respectively.

For example, in some embodiments, as shown in FIG. 1C, the bridgesub-circuit board 200 may be provided to be plural (for example, twobridge sub-circuit boards are shown in the figure), and at this time, aplurality of the bridge sub-circuit boards 200 may be simultaneouslyinstalled on the main body sub-circuit board 100. For example, the mainbody sub-circuit board 100 includes a plurality of first bridgeconnection ends 101 and a plurality of second bridge connection ends102. A plurality of the bridge sub-circuit boards 200 are respectivelyelectrically connected to a plurality of first bridge connection ends101 and a plurality of second bridge connection ends 102 through aplurality of third bridge connection ends 201 and a plurality of fourthbridge connection ends 202 thereon, so as to be installed on the mainbody sub-circuit board 100.

It should be noted that, in the embodiment shown in FIG. 1C, two bridgesub-circuit boards 200 are provided, however, the embodiment of thepresent disclosure is not limited thereto, that is, the number of bridgesub-circuit boards 200 may be selected according to actual requirements,and the embodiments of the present disclosure do not limit the number ofbridge sub-circuit boards 200.

In addition, the embodiments of the present disclosure do notspecifically limit the setting mode of the bridge sub-circuit board 200.For example, in the above embodiment, the bridge sub-circuit board 200is horizontally arranged to bridge wirings at left and right sides ofthe main body sub-circuit board 100, and the wiring in the middle of themain body sub-circuit board 100 passes under the bridge sub-circuitboard 200. In other embodiments, as shown in FIG. 1D, the arrangementdirection of the bridge sub-circuit board 200 may also be provided forvertical bridging, so that wirings at upper and lower sides of the mainbody sub-circuit board 100 are bridged, while the wirings at the leftand right sides of the main body sub-circuit board 100 pass under thebridge sub-circuit board 200.

For example, FIG. 5A shows a schematic plan view of another main bodysub-circuit board provided by an embodiment of the present disclosure.This main body sub-circuit board adopts a different shape and circuitarrangement from the above embodiments.

For example, as shown in FIG. 5 , the main body sub-circuit board is inan elongated shape. The first bridge connection end 101, the secondbridge connection end 102, the first wiring portion 103, the secondwiring portion 104, the second functional wiring 106 and otherstructures of the main body sub-circuit board have similar arrangementsas those of the main body sub-circuit board of the above embodiments.However, compared with the main body sub-circuit board of the aboveembodiments, in the main body sub-circuit board shown in FIG. 5 , thethird wiring portion 107 extends from the middle of the main bodysub-circuit board and turns to the left side of the main bodysub-circuit board at a side (the lower side shown in the figure) of themain body sub-circuit board, and is electrically connected to a terminal111 at the left side of the main body sub-circuit board. The terminal111 is provided with a plurality of contact pads thereon, and aplurality of wirings in the third wiring portion 107 correspond to andare electrically connected to a plurality of contact pads on theterminal 111 one by one. For example, the terminal 111 may beelectrically connected with other display devices or control chips,which is not limited by the embodiments of the present disclosure.

For example, in some embodiments, the main body sub-circuit board may bea single-layer wiring structure or a multi-layer wiring structure (suchas a double-layer wiring structure or a three-layer wiring structure, orthe like), which is not limited by the embodiments of the presentdisclosure.

In some embodiments, an outline shape of the bridge sub-circuit board200 is an asymmetric structure. The second bridge connection end 102 andthe first wiring portion 103 as shown in FIG. 5A are asymmetric.

For example, FIG. 6A shows a schematic cross-sectional view of a mainbody sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line A-A in FIG. 2 . In theseembodiments, the main body sub-circuit board 100 has a single-layerwiring structure. As shown in FIG. 6A, the main body sub-circuit board100 includes a first substrate 1001, as well as a first main body wiringlayer 1002 and a first main body insulating layer 1003 laminated on aside of the first substrate 1001. The first main body wiring layer 1002includes a first wiring portion 103, a second wiring portion 104, afirst bridge connection end 101 and a second bridge connection end 102and other structures. The first bridge connection end 101 and the secondbridge connection end 102 are exposed by the first main body insulatinglayer 1003. For example, the first main body insulating layer 1003serves as a protective layer to provide structural and electricalprotection for the first main body wiring layer 1002. For example, thefirst main body insulating layer 1003 may be combined with the firstmain body wiring layer 1002 and the first substrate 1001 through anadhesive layer (not shown in the figure). For example, an opening 1013is formed in the first main body insulating layer 1003. In the opening1013, for example, a portion of the exposed first wiring layer 1002corresponding to the first bridge connection end 101 or the secondbridge connection end 102 may be subjected to surface treatment (forexample, plated with a solder layer), to form a plurality of patternedcontact pads and correspondingly form the first bridge connection end101 or the second bridge connection end 102.

For example, when the main body sub-circuit board further includes thesecond functional wiring 106 and the third functional wiring 107, thesecond functional wiring 106 and the third functional wiring 107 arealso arranged in the first wiring layer 1002. At this time, the mainbody sub-circuit board has a single-layer wiring structure with asingle-layer wiring layer.

For example, FIG. 6B shows a schematic cross-sectional view of anothermain body sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line A-A in FIG. 2 , for example.In these embodiments, the main body sub-circuit board 100 has amulti-layer wiring structure. The description will be made by taking anexample of the main body sub-circuit board 100 with a double-layerwiring structure with reference to FIG. 6B, however, the embodiments ofthe present disclosure are not limited thereto.

As shown in FIG. 6B, in this example, the main body sub-circuit board100 includes a first substrate 1001, as well as a first main body wiringlayer 1002 and a first main body insulating layer 1003 which are locatedand laminated on the first side (shown as the upper side in the figure)of the first substrate 1001; and also includes a second main body wiringlayer 1004 and a second main body insulating layer 1005 which arelocated and laminated on the second side (shown as the lower side in thefigure) of the first substrate 1001. The first main body insulatinglayer 1003 serves as a protective layer to provide structural andelectrical protection for the first main body wiring layer 1002. Forexample, the first main body insulating layer 1003 may be combined withthe first main body wiring layer 1002 and the first substrate 1001through an adhesive layer (not shown). The second insulating layer 1005serves as a protective layer to provide structural and electricalprotection for the second main body wiring layer 1004. For example, thesecond main body insulating layer 1005 may be combined with the secondmain body wiring layer 1004 and the first substrate 1001 through anadhesive layer (not shown).

For example, in some examples, the first main body wiring layer 1002includes a first wiring portion 103 and a second wiring portion 104. Atthis time, the first wiring portion 103 and the second wiring portion104 may be arranged to be intersected in the first main body wiringlayer 1002 and the second main body wiring layer 1004. For example, twoadjacent ones of the wirings of the first wiring portion 103 on theboard surface of the main body sub-circuit board 100 may be located inthe first main body wiring layer 1002 and the second main body wiringlayer 1004, respectively, thereby facilitating the arrangement ofwirings. For example, the second wiring portion 104 may be similarlyarranged.

For example, when the main body sub-circuit board further includes asecond functional wiring 106 and a third functional wiring 107, whichmay also be intersected in first main body wiring layer 1002 and secondmain body wiring layer 1004. Alternatively, the first main body wiringlayer 1002 may include a first wiring portion 103 and a second wiringportion 104; and the second main body wiring layer 1004 may include asecond functional wiring 106 and a third functional wiring 107, that is,different wiring layers may be arranged with different functionalwirings. The embodiments of the present disclosure do not specificallylimit the wiring layout on the main body sub-circuit board 100.

For example, in the embodiment shown in FIG. 5A, when the first wiringportion 103, the second wiring portion 104, the second functional wiring106 and third functional wiring 107 on the main body sub-circuit board100 are alternately arranged in first main body wiring layer 1002 andthe second main body wiring layer 1004, the first main body wiring layer1002 is schematically shown in FIG. 5A, and the second main body wiringlayer 1004 is schematically shown in FIG. 5B. At this time, the wiringsin the second main body wiring layer 1004 have a similar arrangement asthe wirings in the first main body wiring layer 1002, and the wirings inthe second main body wiring layer 1004 may be electrically connected tothe first main body wiring layer 1002 through via holes (for example,black dots shown in FIG. 5B) and exposed by a corresponding insulatinglayer to form bridge ends.

For example, in some embodiments, as shown in FIG. 6B, the first bridgeconnection end 101 and the second bridge connection end 102 may beexposed by the first main body insulating layer 1003. For example,similarly, an opening 1013 is formed in the first main body insulatinglayer 1003, for example, a portion of the exposed first main body wiringlayer 1002 corresponding to the first bridge connection end 101 or thesecond bridge connection end 102 may be subjected to surface treatmentin the opening 1013, so as to form a plurality of patterned contact padsand correspondingly form the first bridge connection end 101 or thesecond bridge connection end 102. Similarly, the wirings located in thesecond main body wiring layer 1004 pass through the via hole 1011 in thefirst substrate 1001, the first main body wiring layer 1002 and theopening 1013 of the first main body insulating layer 1003 to form thebridge ends. For example, the via hole 1011 in the first substrate 1001and the opening 1013 of the first main body insulating layer 1003 arearranged in a staggered manner, so that the position of the opening 1013is relatively planar in the manufacturing process, and it is easy toform a contact pad.

For example, in some embodiments, the first bridge connection end 101and the second bridge connection end 102 may be exposed at differentsides of the main body sub-circuit board, respectively, so that thefirst bridge connection end 101 and the second bridge connection end 102are disposed at different the sides of the main body sub-circuit board.

For example, FIG. 7A shows a schematic cross-sectional view of a mainbody sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line C-C in FIG. 2 , for example.In this embodiment, the main body sub-circuit board has a single-layerwiring structure. The first bridge connection end 101 of the main bodysub-circuit board is exposed by the first main body insulating layer1003 as shown in FIG. 6A. The second bridge connection end 102 isexposed by the first substrate 1001, so that the first bridge connectionend 101 and the second bridge connection end 102 are arranged atdifferent sides of the main body sub-circuit board.

For example, FIG. 7B shows a schematic cross-sectional view of anothermain body sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line C-C in FIG. 2 , for example.In this embodiment, the main body sub-circuit board has a double-layerwiring structure. The first bridge connection end 101 of the main bodysub-circuit board is exposed by the first main body insulating layer1003, as shown in FIG. 6B; the second bridge connection end 102 isexposed by the second main body insulating layer 1005, so that the firstbridge connection end 101 and the second bridge connection end 102 arearranged at different sides of the main body sub-circuit board.

For example, in some embodiments, the main body sub-circuit board mayalso have a multi-layer wiring structure, for example a three-layerwiring structure and a four-layer wiring structure. At this time, thewirings on the main body sub-circuit board, such as wirings of the firstwiring portion, the second wiring portion, the second functional wiring,and the third functional wiring, may be arranged in a plurality ofwiring layers. For example, the first wiring portion, the second wiringportion, the second functional wiring, and the third functional wiringare alternately arranged in a plurality of wiring layers, or arerespectively arranged in different wiring layers. Embodiments of thepresent disclosure do not specifically limit the number of wiring layersand wiring arrangement of the main body sub-circuit board.

Similarly, the bridge sub-circuit board may also have a single-layerwiring structure or a multi-layer wiring structure. For example, FIG. 8Ashows a schematic cross-sectional view of a bridge sub-circuit boardprovided by some embodiments of the present disclosure, which is takenalong the line B-B in FIG. 3A, for example. In these embodiments, thebridge sub-circuit board 200 has a single-layer wiring structure.

For example, as shown in FIG. 8A, the bridge sub-circuit board 200includes a second substrate 2001, as well as a first bridge wiring layer2002 and a first bridge insulating layer 2003 located at a first side(shown as the upper side in the figure) of the second substrate 2001,and the first bridge wiring layer 2002 includes a third wiring portion203. Similarly, the first bridge insulating layer 2003 serves as aprotective layer to provide structural and electrical protection for thefirst bridge wiring layer 2002. For example, the first bridge insulatinglayer 2003 may be combined with the first bridge wiring layer 2002 andthe second substrate 2001 through an adhesive layer (not shown).

For example, the second substrate 2001 has an opening 2011, for example,a portion of the exposed first bridge wiring layer 2002 corresponding tothe third bridge connection end 201 or the fourth bridge connection end202 may be subjected to surface treatment in the opening 2011, to form aplurality of patterned contact pads and correspondingly form the thirdbridge connection end 201 or the fourth bridge connection end 202.

For example, in some embodiments, as shown in FIG. 8B, the bridgesub-circuit board 200 may further include a shielding layer 2006 whichis disposed at a side of the second substrate 2001 far away from thefirst bridge wiring layer 2002. For example, the shielding layer 2006may be grounded, so as to achieve an effect of electromagneticshielding, and prevent the wirings in the main body sub-circuit boardand the bridge sub-circuit board from occurring signal crosstalk. Forexample, the shielding layer 2006 has a hollowed-out structure 2016,which corresponds to the opening 2011 in the second substrate 2001 toexpose the third bridge connection end 201 or the fourth bridgeconnection end 202.

For example, FIG. 8C shows a schematic cross-sectional view of anotherbridge sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line B-B in FIG. 3A, for example.In these embodiments, the bridge sub-circuit boards 200 has amulti-layer structure. A bridge sub-circuit boards 200 with adouble-layer structure will be taken as an example with reference toFIG. 8C and described below, however, the embodiments of the presentdisclosure are not limited thereto.

As shown in FIG. 8C, the bridge sub-circuit board 200 includes a secondsubstrate 2001, as well as a first bridge wiring layer 2002 and a firstbridge insulating layer 2003 located at a first side (shown as the upperside in the figure) of the second substrate 2001, the first bridgewiring layer 2002 includes a third wiring portion 203. Similarly, thefirst bridge insulating layer 2003 serves as a protective layer toprovide structural and electrical protection for the first bridge wiringlayer 2002. For example, the first bridge insulating layer 2003 may becombined with the first bridge wiring layer 2002 and the secondsubstrate 2001 through an adhesive layer (not shown).

For example, as shown in FIG. 8C, the bridge sub-circuit board 200 mayfurther include a second bridge wiring layer 2004 located at a secondside (shown as the lower side in the figure) opposite to the first sideof the second substrate 2001 and a second bridge insulating layer 2005laminated on the second bridge wiring layer 2004. For example, thesecond bridge wiring layer 2004 may also include a third wiring portions203. At this time, the third wiring portions 203 may be alternatelyarranged in the first bridge wiring layer 2002 and the second bridgewiring layer 2004. For example, two adjacent ones of the wirings of thethird wiring portion 203 on the board surface of the bridge sub-circuitboard 200 may be located in the first bridge wiring layer 2002 and thesecond bridge wiring layer 2004, respectively, thereby facilitatingwiring arrangement. For example, it is shown as the dashed lines in FIG.8D that the wiring portions at both sides of the second bridge wiringlayer 2004 are not electrically connected.

For example, the third wiring portion 203 at the first side of thebridge sub-circuit board 200 is exposed and led out through the via hole2011 in the second substrate 2001 and the opening 2015 in the secondbridge insulating layer 2005, for example, a plurality of patternedcontact pads are formed by surface treatment to form a third bridgeconnection end 201 or a fourth bridge connection end 202. For example,the opening 2015 in the second bridge insulating layer 2005 is formed ata position as shown by the dashed box shown in FIG. 8C or at othersuitable positions, and the embodiment of the present disclosure doesnot limit thereto.

For example, as shown in FIG. 8D, in some embodiments, the bridgesub-circuit board 200 may further include a shielding layer 2006 at asecond side of the second substrate 2001. The shielding layer 2006, forexample, is disposed at a side of the second bridge insulating layer2005 far away from the second substrate 2001. For example, the shieldinglayer 2006 is grounded to achieve an effect of electromagneticshielding. For example, the shielding layer 2006 has a hollowed-outstructure 2016 at a position corresponding to the opening 2015 of thesecond bridge insulating layer 2005, to form the exposed third bridgeconnection end 201 or the fourth bridge connection end 202.

For example, when the bridge sub-circuit board 200 is installed on themain body sub-circuit board 100, the second side is closer to the mainbody sub-circuit board 100 than the first side. Therefore, the shieldinglayer 2006 is located between wiring layers of the main body sub-circuitboard 100 and the bridge sub-circuit board 200, to prevent the signalcrosstalk between the wiring layers of the main body sub-circuit board100 and the bridge sub-circuit board 200.

For example, in some embodiments, the second bridge wiring layer 2004may be a ground layer including a plurality of ground wirings. At thistime, the third wiring portion 203 may entirely be disposed in the firstbridge wiring layer 2002. Therefore, a ground layer is further providedbetween the wiring layers of the main body sub-circuit board 100 and thebridge sub-circuit board 200, to further prevent the signal crosstalkbetween the wiring layers of main body sub-circuit board 100 and bridgesub-circuit board 200. Alternatively, in some embodiments, the thirdwiring portion 203 may has a part disposed in the first bridge wiringlayer 2002 and another part disposed in the second bridge wiring layer2004. At this time, the ground wirings in the second bridge wiring layer2004 and some of the wirings of the third wiring portion 203 may bealternately arranged. Therefore, the second bridge wiring layer 2004 canalso play a role in preventing the signal crosstalk.

When the bridge sub-circuit board has both the ground layer and theshielding layer 2006, the ground layer 2004 and the shielding layer 2006can achieve the double shielding effect, thus prevent the signalcrosstalk between the wirings on the main body sub-circuit board 100 andthe wirings on the bridge sub-circuit board 200.

For example, in some embodiments, the bridge sub-circuit board 200 mayfurther include an insulating layer (not shown) outside the shieldinglayer 2006 (i.e., a side far away from the second substrate 2001) toprovide protection for the shielding layer 2006, and the insulatinglayer may be combined with the shielding layer 2006 by an adhesivelayer, for example. The insulating layer may also include openingscorresponding to the openings 2015 and the hollowed-out structures 2016to expose the bridge ends. For example, the via hole 2011 in the secondsubstrate 2001 and the opening 2015 of the second bridge insulatinglayer 2005 are arranged in a staggered manner, so that the position ofthe opening 1015 is relatively planar in the manufacturing process, andit is easy to form a contact pad.

For example, in some embodiments, the third bridge connection end 201 orthe fourth bridge connection end 202 of the bridge sub-circuit board 200may be respectively exposed at different sides of the bridge sub-circuitboard 200, so that the third bridge connection end 201 and the fourthbridge connection end 202 are disposed at different sides of the bridgesub-circuit board 200.

For example, FIG. 9A shows a schematic cross-sectional view of anotherbridge sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line D-D in FIG. 3A, for example.In this embodiment, the bridge sub-circuit board has a single-layerwiring structure. For example, the third bridge connection end 201 ofthe bridge sub-circuit board is exposed by the second substrate 2001, asshown in FIG. 8A; the fourth bridge connection end 202 is exposed by anopening 2013 in the first bridge insulating layer 2003, as shown in FIG.9A, so that the third bridge connection end 201 and the fourth bridgeconnection end 202 are arranged at different sides of the bridgesub-circuit board.

For example, FIG. 9B shows a schematic cross-sectional view of anotherbridge sub-circuit board provided by some embodiments of the presentdisclosure, which is taken along the line D-D in FIG. 3A, for example.In this embodiment, the bridge sub-circuit board has a double-layerwiring structure. For example, the third bridge connection end 201 ofthe bridge sub-circuit board is exposed by the second bridge insulatinglayer 2005, as shown in FIG. 8C; the fourth bridge connection end 202 isexposed by the opening 2013 in the first bridge insulating layer 2003,as shown in FIG. 9B, so that the third bridge connection end 201 and thefourth bridge connection end 202 are disposed at different sides of thebridge sub-circuit board.

For example, in some embodiments, the bridge sub-circuit board may alsohave a multi-layer wiring structure, for example a three-layer wiringstructure and a four-layer wiring structure. At this time, the thirdwiring portion on the bridge sub-circuit board may be arranged in aplurality of wiring layers. For example, the third wiring portion may bealternately arranged in a plurality of wiring layers. Embodiments of thepresent disclosure do not specifically limit the number of wiring layersand the arrangement of wirings of the bridge sub-circuit board.

For example, in some embodiments, when the first bridge connection end101 and the second bridge connection end 102 of the main bodysub-circuit board are arranged at different sides of the main bodysub-circuit board, and the third bridge connection end 201 and thefourth bridge connection end 202 of the bridge sub-circuit board arealso respectively arranged at different sides of the bridge sub-circuitboard, the third bridge connection end 201 and the fourth bridgeconnection end 202 of the bridge sub-circuit board may be electricallyconnected to the first bridge connection end 101 and the second bridgeconnection end 102 at different sides of the main body sub-circuitboard, respectively. Alternatively, when the first bridge connection end101 and the second bridge connection end 102 of the main bodysub-circuit board are arranged at different sides of the main bodysub-circuit board, and the third bridge connection end 201 and thefourth bridge connection end 202 of the bridge sub-circuit board arearranged at the same side of the bridge sub-circuit board, the thirdbridge connection end 201 and the fourth bridge connection end 202 ofthe bridge sub-circuit board may be folded to be electrically connectedto the first bridge connection end 101 and the second bridge connectionend 102 at different sides of the main body sub-circuit board, so thatthe bridge sub-circuit board may be bridged on the main body sub-circuitboard in a form similar to “hair clip”.

For example, the first substrate 1001 and the second substrate 2001 maybe made of flexible materials such as polyimide or polyester; the wiringlayers may be made of metal materials such as copper, silver andaluminum or alloy materials; the insulating layers may be made ofinsulating materials such as polyimide or polyester; and the groundlayer 2004 may be made of a metal material such as copper layer orcopper foil. The shielding layer 2006 includes an insulating substrateand a conductive material filled in the insulating substrate, forexample, the insulating substrate is epoxy resin, and the filledconductive material is copper powder, graphite powder, or the like.Alternatively, in some embodiments, the shielding layer 2006 may also bemade of a metal material. The materials of functional layers are notspecifically limited in this disclosure. The adhesive layer adopts epoxyresin, polyethylene, or the like.

For example, the third bridge connection end 201 and the fourth bridgeconnection end 202 of the bridge sub-circuit board 200 are connected tothe first bridge connection end 101 and the second bridge connection end102 of the main body sub-circuit board 100 through anisotropicconductive adhesive, soldering material or connectors, respectively. Forexample, the connector includes a zero insertion force (ZIF) connector,a board to board (BTB) connector, or the like. The embodiments of thepresent disclosure do not specifically limit the connection mode ofbridge ends.

As an example, a BTB connector is used to connect the main bodysub-circuit board 100 and the bridge sub-circuit board 200. At thistime, the connector includes a male connector and a female connectorcooperated with each other. For example, the first bridge connection end101 and the second bridge connection end 102 of the main bodysub-circuit board 100 are provided with female connectors, the thirdbridge connection end 201 and the fourth bridge connection end 202 ofthe bridge sub-circuit board 200 are provided with male connectors, sothat the bridge sub-circuit board 200 is connected to the main bodysub-circuit board 100 through plug-in of male connectors and femaleconnectors.

The flexible circuit board provided by the embodiment of the presentdisclosure has a main body sub-circuit board and a bridge sub-circuitboard, and the wirings at both sides of the main body sub-circuit boardmay be bridged by the bridge sub-circuit board, to avoid theintersection of the wirings on the main body sub-circuit board, preventor weaken the signal crosstalk, or avoid adding additional functionallayers for preventing signal crosstalk, and thus avoid the complexity ofthe circuit board structure. In some embodiments of the presentdisclosure, the main body sub-circuit board and the bridge sub-circuitboard have a simple single-layer structure or a double-layer structure,so as to make the wiring layout simpler, and reduce the manufacturingdifficulty of the main body sub-circuit board and the bridge sub-circuitboard.

Some embodiments of the present disclosure provide an electronic devicemodule, and FIG. 10A shows a schematic view of the electronic devicemodule. As shown in FIG. 10A, the electronic device module 1 includes anelectronic device substrate 11 and any one of the flexible circuitboards 10 described above. The electronic device substrate 11 includes afirst functional circuit structure 20. The first functional wiring thatincludes the first wiring portion 103, the second wiring portion 104 andthe third wiring portion 203 of the flexible circuit board 10 iselectrically connected to the first functional circuit structure 20.

For example, in some embodiments, the flexible circuit board 10 furtherincludes a second functional wiring 106, and the first functionalcircuit structure 20 includes a first signal transmission portion 21 anda second signal transmission portion 22.

For example, in some embodiments, the electronic device substrate 11further includes a second functional circuit structure 23, the flexiblecircuit board further includes a third functional wiring 107electrically connected to the second functional circuit structure 23.

For example, in some embodiments, the electronic device substrate 11 isa substrate with a display function and a touch function. At this time,the first functional circuit structure 20 is a touch circuit structure,and the second functional circuit structure 23 is a display circuitstructure. In other embodiments, the electronic device substrate 11 is asubstrate with a display function and a fingerprint recognitionfunction. In this case, the first functional circuit structure 20 is afingerprint recognition circuit structure, for example, a capacitivefingerprint recognition circuit, which includes a detection drivingelectrode and a detection sensing electrode that are arranged crosswise.The second functional circuit structure 23 is a display circuitstructure. The first functional circuit structure 20 with a touchcircuit structure will be taken as an example and described below.

For example, the arrangement of the touch circuit structure on theelectronic device substrate 11 may be in a built-in manner or in abuilt-out manner. The touch circuit structure may be in a capacitiveform, such as a mutual capacitive touch circuit structure. For example,the mutual capacitive touch circuit structure includes a plurality offirst electrodes extending in a first direction and a plurality ofsecond electrodes extending in a second direction intersecting the firstdirection, and a detection capacitor is formed at a position where twogroups of electrodes intersect, that is, these two groups of electrodesrespectively form two poles of the capacitor. When the touch circuitstructure is touched by a finger, the finger will affect the couplingstate between two electrodes close to the touch point, so as to changethe capacitance of the detection capacitor between these two electrodes.According to the capacitance variation data of the touch circuitstructure and coordinates of capacitances, the coordinates of each touchpoint can be obtained. When a size of the capacitance is detected,transverse electrodes are used as touch driving circuits to sendsequentially excitation signals, and longitudinal electrodes are used astouch sensing circuits to receive signals simultaneously orsequentially, so that capacitance values of intersection points of alltransverse and longitudinal electrodes can be obtained, that is, acapacitance value of a two-dimensional plane of the whole touchstructure can be obtained. Therefore, even if there are several touchpoints on the touch structure, a real coordinate of each touch point canbe determined.

For example, in the situation as mentioned above, the first signaltransmission portion 21 may include a touch driving wiring electricallyconnected to a touch driving (Tx) circuit of the touch circuit, and thesecond signal transmission portion 22 may include a touch sensing wiringelectrically connected to a touch sensing (Rx) circuit of the touchcircuit. At this time, the first control circuit 1051 is a touch drivingIC, and may provide excitation signals for the touch driving circuitthrough the touch driving wiring, receive induction signals from thetouch sensing circuit through the touch sensing wiring, judge a touchposition based on the above signals and make a response. For example, inthe above example, the touch driving circuit is bridged and the touchsensing circuit is directly electrically connected to the first controlcircuit combination structure 105, so that the touch sensing circuit iscloser to the first control circuit combination structure 105, that is,closer to the first control circuit 1051 installed thereon (i.e., thetouch driving IC), so that a path for transmitting the sensing signalreceived by the touch sensing circuit to the touch driving IC is short,and the possibility that the sensing signal is interfered by signals issmall, thereby ensuring the touch operation more accurate. For example,as shown in the figure, the touch driving wiring and the touch sensingwiring extend to the same side (the lower side in the figure) of theelectronic device substrate 11, and are electrically connected to thecontact pads 211 and 221 formed on this side, respectively.

For example, in other embodiments of the present disclosure, the firstsignal transmission portion 21 may include a touch sensing wiringelectrically connected to a touch sensing (Rx) circuit of the touchcircuit, and the second signal transmission portion 22 may include atouch driving wiring electrically connected to a touch driving (Tx)circuit of the touch circuit. At this time, the touch sensing circuit isbridged, and the touch driving circuit is directly electricallyconnected to the first control circuit combination structure 105, sothat the touch driving circuit is closer to the first control circuitcombination structure 105, that is, closer to the first control circuit1051 installed thereon, (i.e., the touch driving IC), so that in thisembodiment, the touch driving signal in the touch driving circuit isless likely to be interfered by signals.

For example, the flexible circuit board 10 has a terminal 110 at a sidethereof (e.g., the upper side in the figure), and the terminal 110 has aplurality of contact pads thereon. Another ends of a plurality ofwirings of the second wiring portion 104 are electrically connected tosome of the contact pads in the terminal 110 in one-to-onecorrespondence; another ends of a plurality of wirings of the secondfunctional wiring 106 are electrically connected to some other of thecontact pads in the terminal 110 in one-to-one correspondence, andanother ends of a plurality of wirings of the third functional wiring107 are electrically connected to some further of the contact pads inthe terminal 110 in one-to-one correspondence. For example, some contactpads respectively electrically connected to the second wiring portion104, the third functional wiring 107; and the second functional wiring106 are arranged at intervals or continuously at the terminal 110, whichis not specifically limited by the embodiments of the presentdisclosure. For example, when there are many wirings in the secondwiring portion 104, the third functional wiring 107, and the secondfunctional wiring 106, the contact pads connected thereto may becontinuously arranged at the terminal 110. When there are few wirings inthe second wiring portion 104, the third functional wiring 107, and thesecond functional wiring 106, the contact pads connected thereto may bearranged at intervals at the terminal 110. At this time, for example, aplurality of groups of contact pads spaced apart as shown in FIG. 10Amay be formed.

For example, the terminal 110 is arranged in the wiring area 110A of themain body sub-circuit board (i.e., the diagonal line area below theterminal 110 in the figure). For example, the wiring area 110A only hasa wiring layer and a part of an insulation layer, but does not have ashielding layer or other structures, so the wiring area 110A has a greattransparency. In the process of bonding the flexible circuit board 10 tothe electronic device substrate 11, a clear alignment can be realized soas to facilitate accurate electrical connection between the flexiblecircuit board 10 and the electronic device substrate 11.

For example, when the flexible circuit board 10 is combined with theelectronic device substrate 11, contact pads of the terminal 110 at theside of the flexible circuit board 10 and contact pads at the side ofthe electronic device substrate 11 may be directly pressure-moldedtogether. For example, in some embodiments, contact pads of the terminal110 at the side of the flexible circuit board 10 and contact pads at theside of the electronic device substrate 11 are electrically connected toeach other through, for example, ACF, so that the first functionalwiring on the flexible circuit board 10 is electrically connected withthe touch driving wiring connected to the first signal transmissionportion 21 through the contact pads 211, and the second functionalwiring on the flexible circuit board is electrically connected with thetouch sensing wiring connected to the second signal transmission portion22 through the contact pads 221, such that the first functional wiringand the second functional wiring of the flexible circuit board 10 areelectrically connected with the touch circuit structure of theelectronic device substrate 11.

For example, the second functional circuit structure 23 (i.e., thedisplay circuit structure) includes a plurality of data lines (and alsoincludes gate lines and the like). A plurality of the data lines arerespectively electrically connected to pixel units, and extend to a side(the lower side in the figure) of the electronic device substrate 11 andare electrically connected to the contact pads 231 formed at this side.In the case of an organic light emitting diode (OLED) display substrate,the pixel unit includes a display driving circuit, for example, thedisplay driving circuit includes a plurality of transistors, capacitors,light emitting devices, and the like, and is formed in various formssuch as 2T1C, 3T1C or 7T1C. For example, when the flexible circuit board10 is combined with the electronic device substrate 11, a plurality ofcontact pads are provided on the terminal 110 of the flexible circuitboard 10, the third functional wiring on the flexible circuit board isfurther electrically connected to the data lines in the secondfunctional circuit structure 23 through the contact pads 231, such thatthe third functional wiring of the flexible circuit board 10 iselectrically connected with the display circuit structure of theelectronic device substrate 11.

For example, in some embodiments, as shown in FIG. 10B, the main bodysub-circuit board 100 may also have a second control circuit combinationstructure 108 and a second control circuit 1081 disposed on the secondcontrol circuit combination structure 108. At this time, the secondcontrol circuit 1081 is a display driving IC, which may provide datasignals for the display driving circuit, to control the light-emittingstate of the light-emitting device through the data signals provided bythe display driving IC, so that different display effects can berealized.

As for a liquid crystal display (LCD) substrate, the pixel unit includesa switching element, and a first electrode (a pixel electrode) and asecond electrode (a common electrode) for controlling liquid crystaldeflection, and the switching element is electrically connected to thefirst electrode. The second functional circuit structure 23 (i.e., thedisplay circuit structure) includes a plurality of data linesrespectively connected to the pixel units. At this time, the secondcontrol circuit is a display driving IC, and may provide different datavoltage signals to the pixel units through the data lines, to controlthe torsion state of the liquid crystal, so as to realize differentdisplay effects.

For example, the flexible circuit board is combined with the electronicdevice substrate 11 in a binding manner. When the electronic devicesubstrate 11 is bound, the flexible circuit board may be folded to aback of the electronic device substrate 11 and fixed, that is, installedon a non-display side of the electronic device substrate 11, so as tofacilitate the large-screen design of the display screen.

In the flexible circuit board of the electronic device substrate in someembodiments of the present disclosure, the wiring portions located onthe main body sub-circuit board and respectively electrically connectedto the touch driving circuit are bridged by the bridge sub-circuitboard, so that the touch driving circuit does not intersect the displaydriving circuit on the main body sub-circuit board, and they areshielded from each other at the intersection of the main bodysub-circuit board and the bridge sub-circuit board, thereby avoiding thewirings in the main body sub-circuit board and the bridge sub-circuitboard from occurring the signal crosstalk; meanwhile, the main bodysub-circuit board and the bridge sub-circuit board have simple structureand wiring layout, which is beneficial to simplify the manufacturingprocess.

At least one embodiment of the present disclosure provides a displaydevice, and FIG. 11 shows a schematic view of the display device. Asshown in FIG. 11 , the display device 2 includes any of the electronicdevice modules described above, and the electronic device moduleincludes an electronic device substrate 11 and a flexible circuit board10. For example, the upper side of the electronic device substrate 11shown in FIG. 11 is a display side and the lower side thereof is anon-display side. At this time, the flexible circuit board 10 is foldedand placed at the non-display side of the electronic device substrate 11after being bound, so as to realize the large-screen design of thedisplay screen.

The display device 2 may be, for example, a mobile phone, a tabletcomputer, a television, a display, a notebook computer, a digital photoframe, a navigator, and any other products or components with displayfunctions, which are not specifically limited by the embodiments of thepresent disclosure.

Some embodiments of the present disclosure provide a manufacturingmethod of flexible circuit board, as shown in FIG. 12 , which includessteps S101-S103.

S101: providing a main body sub-circuit board.

With reference to FIG. 2 , the main body sub-circuit board 100 includesa first bridge connection end 101, a second bridge connection end 102, afirst wiring portion 103 and a second wiring portion 104. The firstwiring portion 103 and the second wiring portion 104 are spaced apartfrom each other and electrically connected to the first bridgeconnection end 101 and the second bridge connection end 102,respectively.

For example, referring to FIG. 6A, the main body sub-circuit board 100is formed by sequentially forming a first wiring layer 1002 and a firstinsulating layer 1003 on a first substrate 1001. For example, the firstsubstrate 1001 is made of polyimide or polyester, the first wiring layer1002 is made of a metal material such as copper, silver and aluminum oran alloy material, and the first insulating layer 1003 is also made ofpolyimide, polyester, or the like. For example, firstly, a copper metallayer is formed on the first substrate 1001 by sputtering, and then thecopper metal layer is patterned to form the first wiring layer 1002.Then, a first insulating layer 1003 is formed on the first wiring layer1002 by coating, and an opening is formed in the first insulating layer1003 to form a bridge end.

S102: providing a bridge sub-circuit board.

With reference to FIG. 3 , the bridge sub-circuit board 200 includes athird bridge connection end 201, a fourth bridge connection end 202 anda third wiring portion 203; and the third bridge connection end 201 andthe fourth bridge connection end 202 are electrically connected by thethird wiring portion 203.

For example, referring to FIG. 8A, the bridge sub-circuit board 200 isformed by sequentially forming a first bridge wiring layer 2002 and afirst bridge insulating layer 2003 at a first side of a second substrate2001. For example, the first substrate 2001 is made of a material suchas polyimide or polyester, the first bridge wiring layer 2002 is made ofa metal material such as copper, silver and aluminum or an alloymaterial, and the first bridge insulating layer 2003 is also made of amaterial such as polyimide or polyester. For example, a copper metallayer is formed on the first substrate 2001 by sputtering, and then thecopper metal layer is patterned to form the first bridge wiring layer2002, and then the first bridge insulating layer 2003 is formed on thefirst bridge wiring layer 2002 by coating.

For example, referring to FIG. 8C, in some embodiments, forming thebridge sub-circuit board 200 further includes sequentially forming asecond bridge wiring layer 2004 and a second bridge insulating layer2005 at a second side of the second substrate 2001 opposite to the firstside. For example, the second bridge wiring layer 2004 may be a groundlayer made of a material such as copper, and the second bridgeinsulating layer 2005 is made of a material such as polyimide orpolyester. For example, in the second substrate 2001 and the secondbridge insulating layer 2005, openings (or via holes) are formed bypatterning, a third wiring portion 203 formed at a first side of thebridge sub-circuit board 200 is exposed and led out through a via hole2011 in the second substrate 2001 and an opening 2015 in the secondbridge insulating layer 2005. For example, a plurality of contact padsare formed by surface treatment to form a bridge end.

For example, with continued reference to FIG. 8C, in some embodiments,forming the bridge sub-circuit board 200 further includes forming ashielding layer 2006 at a second side of the second substrate 2001. Forexample, the shielding layer 2006 is, for example, suspended, orconfigured to be electrically connected to a ground line.

For example, in some embodiments, as shown in FIG. 8D, when the secondbridge wiring layer 2004 is a ground layer, an opening 2025 is alsoformed in the second bridge insulating layer 2005, and the shieldinglayer 2006 is electrically connected to the ground wiring in the secondbridge wiring layer 2004 through the opening 2025.

In the FIGS. 6B to 8D above, the shapes, for example the sectional viewsof the via hole 1011 and the opening 2011 are inverted H shapes. Asviewed from the top view, an external diameter of a side in contact withthe first main body wiring layer 1002 and the first bridge wiring layer2002 is larger than an external diameter of a layer located in the firstsubstrate 1001 and the second substrate 2001, and an external diameterof a side in contact with the second main body wiring layer 1004 and thesecond bridge wiring layer 2004 is larger than an external diameter of alayer located in the first substrate 1001 and the second substrate 2001.

The via hole 1011 and the opening 2011 make the upper and lower layers(the first main body wiring layer 1002 and the second main body wiringlayer 1004, the first bridge wiring layer 2002 and the second bridgewiring layer 2004) electrically connected.

For example, when the second bridge wiring layer 2004 is a ground layer,the ground layer 2004 and the shielding layer 2006 can function as adouble shielding to prevent signal crosstalk between wirings on the mainbody sub-circuit board 100 and wirings on the bridge sub-circuit board200. For example, the shielding layer 2006 has a hollowed-out structure2016 formed at a position corresponding to the opening 2015 of thesecond bridge insulating layer 2005 to expose a bridge end.

For example, the shielding layer 2006 includes an insulating substrateand a conductive material filled in the insulating substrate. Forexample, the insulating substrate is made of epoxy resin, and the filledconductive material is copper powder, graphite powder, or the like.Alternatively, in some embodiments, the shielding layer 2006 may also bemade of a metal material, which is not specifically limited by theembodiments of the present disclosure. For example, the shielding layermay be directly attached to the second side of the bridge sub-circuitboard 200 after being formed.

S103: installing the bridge sub-circuit board on the main bodysub-circuit board.

With reference to FIG. 1A, the third bridge connection end 201 and thefourth bridge connection end 202 of the bridge sub-circuit board 200 arerespectively electrically connected to the first bridge connection end101 and the second bridge connection end 102 of the main bodysub-circuit board 100, so that the bridge sub-circuit board 200 isinstalled on the main body sub-circuit board 100, and the first wiringportion 103, the third wiring portion 203 and the second wiring portion104 are sequentially electrically connected to obtain the firstfunctional wiring. When being installed, the second side of bridgesub-circuit board 200 is closer to the main body sub-circuit board 100than the first side thereof, so that wirings on the main bodysub-circuit board 100 and the bridge sub-circuit board 200 may beshielded by the ground layer 2004 and the shielding layer 2006, toprevent signal crosstalk.

For example, the third bridge connection end 201 and the fourth bridgeconnection end 202 of the bridge sub-circuit board 200 may berespectively connected to the first bridge connection end 101 and thesecond bridge connection end 102 of the main body sub-circuit board 100by hot pressing, welding or connectors. For example, in the manner ofhot pressing, an anisotropic conductive adhesive is formed between twobridge ends, and then the bridge ends are hot pressure-molded to connectthese two bridge ends together by the anisotropic conductive adhesive.For example, the connector includes a zero insertion force (ZIF)connector or a board to board (BTB) connector, and the embodiments ofthe present disclosure do not specifically limit the connection mode.

In an example, for example, a BTB connector is used to connect the mainbody sub-circuit board 100 and the bridge sub-circuit board 200. At thistime, the connector includes a male connector and a female connectorcooperated with each other. For example, the first bridge connection end101 and the second bridge connection end 102 of the main bodysub-circuit board 100 are provided with female connectors, the thirdbridge connection end 201 and the fourth bridge connection end 202 ofthe bridge sub-circuit board 200 are provided with male connectors, sothat the bridge sub-circuit board 200 may be connected to the main bodysub-circuit board 100 through plug-in of the male connector and thefemale connector.

The manufacturing method of the flexible circuit board provided by theembodiment of the present disclosure provides a main body sub-circuitboard and a bridge sub-circuit board, and wirings at both sides of themain body sub-circuit board are bridged by the bridge sub-circuit board.This method can avoid the wirings from intersecting on the main bodysub-circuit board, prevent or weaken signal crosstalk, or avoid addingadditional functional layers to prevent the signal crosstalk, and thusavoid complexity of the circuit board structure. In addition, the mainbody sub-circuit board and the bridge sub-circuit board provided by themanufacturing method have a simple single-layer structure or adouble-layer structure, so as to make the wiring layout simpler, andreduce the manufacturing difficulty of the main body sub-circuit boardand the bridge sub-circuit board.

Following points need to be explained:

(1) the drawings of the embodiments of this disclosure only refer tostructures related to the embodiments of this disclosure, otherstructures may refer to the general designs;

(2) for the sake of clarity, in the drawings for describing theembodiments of the present disclosure, the thickness of a layer or anarea is increased or decreased, that is, these drawings are not drawn tothe actual scale. It can be understood that when an element such as alayer, a film, an area or a substrate is referred to as being formed“above” or “below” another element, the element may be “directly” formed“above” or “below” another element, or formed with intervening elementstherebetween;

(3) the embodiments and the features in the embodiments of the presentdisclosure may be combined with each other with any conflict to obtainnew embodiments.

The exemplary embodiment also provides a circuit board structure, andFIG. 13 is a schematic structural view of a main circuit board in anexemplary embodiment of the circuit board structure of the presentdisclosure. FIG. 14 is a schematic structural view of a transfer circuitboard in an exemplary embodiment of the circuit board structure of thepresent disclosure, and FIG. 15 is a schematic structural view of anexemplary embodiment of the circuit board structure of the presentdisclosure. As shown in FIGS. 13, 14 and 15 , the circuit boardstructure includes a main circuit board 1111, a transfer circuit board222 and a connector 3. The main circuit board has a double circuit layerstructure and carries a main board lapping end 4; the transfer circuitboard 222 has a double circuit layer structure laminated on the maincircuit board 1111 and carries a first element lapping end 51 forlapping a first element set, a first leading wire set 61 connected tothe first element lapping end 51, and a transfer board lapping end 7connected to the first leading wire set 61; the connector 3 is disposedbetween the main circuit board 1111 and the transfer circuit board 222,for connecting the main board lapping end 4 and the transfer boardlapping end 7.

In the circuit board structure provided by the present disclosure, acircuit layer may be provided on each of the main circuit board and thetransfer circuit board, and the circuit layers may include circuitleading wires and device lapping ends. On the one hand, the circuitboard structure provided by the present disclosure can realize thelamination arrangement of circuit layers by laminating the main circuitboard layer and the transfer circuit board, to reduce the occupied spaceof the circuit board structure; on the other hand, the double circuitlayer circuit board has a mature manufacturing process and simplestructural design, to reduce the design cost of the circuit board.

In this exemplary embodiment, the number of the transfer circuit boardis one, however, it should be understood that the number of the transfercircuit board may be plural in other exemplary embodiments.

In this exemplary embodiment, any one of the transfer board lapping end7 and the main board lapping end 4 may be a pin set. When the transfercircuit board and the main circuit board are laminated, the main boardlapping end 4 may be disposed at a side of the main circuit board facingthe transfer circuit board; the transfer board lapping end 7 may bedisposed at a side of the transfer circuit board facing away from themain circuit board, or at a side of the transfer circuit board facingthe main circuit board. The connector may be a plug-in connector, asnapping connector, a soldering connector, or the like. For example, theconnector may be a snapping connector, and the transfer board lappingend 7 may be disposed at a side of the transfer circuit board facing themain circuit board. The snapping connector may include a firstconnecting portion and a second connecting portion, the first connectingportion may be fixed to a side of the transfer circuit board facing themain circuit board to connect the transfer board lapping end 7, and thesecond connecting portion may be fixed on the main circuit board toconnect the main board lapping end 4. The electrical connection betweenthat transfer board lapping end 7 and the main board lapping end 4 canbe realize by snapping the first connecting portion and the secondconnecting portion. In another example, the connector may be a solderingconnector, and the transfer board lapping end 7 may be disposed at aside of the transfer circuit board facing away from the main circuitboard. In this connection mode, corresponding pins in the transfer boardlapping end 7 and the main board lapping end 4 may be soldered by asolder paste.

In this exemplary embodiment, FIG. 16 is a structural schematic view ofanother exemplary embodiment of the circuit board structure of thepresent disclosure. As shown in FIG. 16 , a second leading wire set 62may be arranged on the main circuit board, and an orthographicprojection of the transfer circuit board 222 on the main circuit board1111 covers at least a part of the second leading wire set 62. The firstleading wire set 61 and the second leading wire set 62 are laminated soas to reduce the occupied space of the circuit board structure.

In this exemplary embodiment, as shown in FIG. 16 , the main circuitboard may also carry a second element lapping end 52 for lapping thesecond group of elements, and the second element lapping end 52 may beconnected to the second leading wire set 62. The second element lappingend 52 may be located at a position other than the orthographicprojection of the transfer circuit board on the main circuit board.

In this exemplary embodiment, a connector may be selected from a ZIFconnector or a BTB connector, which has a small impedance and a stableperformance, a lapping resistance value may be less than 10Ω, and theimpedances of lapping channels have good consistence. Compared with thecircuit board structure with a six-layer board, the circuit boardstructure provided by this embodiment has few difference in powerconsumption test data.

In this exemplary embodiment, as shown in FIG. 16 , the main circuitboard also carries a first group of external pins 91; a part of thefirst group of external pins 91 is connected with the main board lappingend 4 to connect a part of the first leading wire set 61, and a part ofthe first group of external pins 91 is connected to the second leadingwire set 62. In this exemplary embodiment, as shown in FIG. 16 , themain circuit board also carries a second group of external pins 92; apart of the second group of external pins 92 is connected to the secondleading wire set 62, and a part of the second group of external pins 92is connected with the main board lapping end 4 to connect a part of thefirst leading wire set.

In this exemplary embodiment, the first group of external pins 91 andthe second group of external pins 92 may be externally connected to asignal terminal. For example, the circuit board structure may be appliedto a display panel, the first group of external pins 91 may be connectedto the signal terminal of the display panel, and the second group ofexternal pins 92 may be connected to an external chip. The first leadingwire set 61 may be used to transmit a touch-related signal, the secondleading wire set 62 may be used to transmit a display-related signal,the first element lapping end 51 may be used to lap a touch-relatedchip, and the second element lapping end 52 may be used to lap adisplay-related chip. For transmission of the touch-related signal, thedisplay panel outputs a touch-related signal which is transmitted to thefirst element lapping end 51 through a part of the first group ofexternal pins 91, the main board lapping end, the connector, thetransfer board lapping end and a part of the first leading wire set 61;the touch-related chip connected to the first element lapping end 51receives the touch-related signal and outputs another touch-relatedsignal which is output to the second group of external pins 92 through apart of the first leading wire set 61, the transfer board lapping end,the connector and the main board lapping end. For the transmission ofthe display related signal, the display related signal is transmitted tothe second element lapping end 52 through a part of the first group ofexternal pins 91 and the second leading wire set 62, the display relatedchip connected to the second element lapping end 52 receives the displayrelated signal and outputs another display related signal which isoutput to the second group of external pins 92.

It should be understood that the first leading wire set 61 may also beused to transmit other related signals, such as a fingerprint unlockingrelated signal and a brightness sensing related signal. The circuitboard structure may also be applied to other technical fields other thandisplay panels, which all are within the protection scope of thisdisclosure.

In this exemplary embodiment, FIG. 17 is a structural schematic view ofan exemplary embodiment of the circuit board structure of the presentdisclosure. As shown in FIG. 17 , the circuit board structure mayfurther include a shielding layer 8 laminated between the main circuitboard 1111 and the transfer circuit board 222. The orthographicprojection of the transfer circuit board 222 may be located on theshielding layer 8 which may be used to shield signals of circuits on themain circuit board and the transfer circuit board. The shielding layermay be an EMI shielding layer.

In this exemplary embodiment, the main board lapping end includes aplurality of main sub-board lapping ends, the transfer board lapping endincludes a plurality of transfer sub-board lapping ends, and theconnector may be in plural. The main sub-board lapping ends and thetransfer sub-board lapping ends are connected in one-to-onecorrespondence through the connectors. The number of main sub-boardlapping ends may be provided according to the actual situation. Forexample, FIG. 18 is a schematic structural view of the main circuitboard in an exemplary embodiment of the circuit board structure, FIG. 19is a schematic structural view of the transfer circuit board in anexemplary embodiment of the circuit board structure, and FIG. 20 is aschematic structural view of an exemplary embodiment of the circuitboard structure. As shown in FIGS. 18, 19 and 20 , the main boardlapping end 4 may include two main sub-board lapping ends 41 and 42, andthe two main sub-board lapping ends 41 and 42 may be respectivelydisposed at opposite sides of the second leading wire set 62.Accordingly, the transfer board lapping end 7 may include two transfersub-board lapping ends 71 and 72. The main sub-board lapping end 41 isconnected to the transfer sub-board lapping end 71 through the connector31, and the main sub-board lapping end 42 is connected to the transfersub-board lapping end 72 through the connector 32.

In this exemplary embodiment, at least one of the main circuit board andthe transfer circuit board may be a flexible circuit board. It should beunderstood that, in other exemplary embodiments, the main circuit boardor the transfer circuit board may also be a non-flexible circuit board,which all are within the protection scope of this disclosure.

In this exemplary embodiment, the main circuit board may include a firstsubstrate and circuit layers located at both sides or a circuit layer ata side of the first substrate, wherein the circuit layers at both sidesof the first substrate may be electrically connected through a via holeon the substrate; the transfer circuit board may include a secondsubstrate and circuit layers at both sides or a circuit layer at a sideof the second substrate, wherein the circuit layers at both sides of thesecond substrate may be electrically connected through a via hole on thesubstrate.

The exemplary embodiment also provides a display panel including thecircuit board structure described above. The display panel may beapplied to a display device such as a television, a mobile phone and atablet computer.

The present disclosure may include dedicated hardware implementationssuch as application specific integrated circuits, programmable logicarrays and other hardware devices. The hardware implementations can beconstructed to implement one or more of the methods described herein.Examples that may include the apparatus and systems of variousimplementations can broadly include a variety of electronic andcomputing systems. One or more examples described herein may implementfunctions using two or more specific interconnected hardware modules ordevices with related control and data signals that can be communicatedbetween and through the modules, or as portions of anapplication-specific integrated circuit. Accordingly, the systemdisclosed may encompass software, firmware, and hardwareimplementations. The terms “module,” “sub-module,” “circuit,”“sub-circuit,” “circuitry,” “sub-circuitry,” “unit,” or “sub-unit” mayinclude memory (shared, dedicated, or group) that stores code orinstructions that can be executed by one or more processors. The modulerefers herein may include one or more circuit with or without storedcode or instructions. The module or circuit may include one or morecomponents that are connected.

The present disclosure is described merely through aforesaid specificimplementations, but the protection scope of the present disclosure isnot limited thereto. Any person skilled in the art may easily think ofvariations or substitutions within the technical scope as disclosed inthe present disclosure, which all should be contained within the scopeof the disclosure.

What is claimed is:
 1. A flexible circuit board comprising: a main body sub-circuit board comprising a first substrate, and a first bridge connection end, a second bridge connection end, a first wiring portion and a second wiring portion on the first substrate, in which the first wiring portion and the second wiring portion are separated from each other and electrically connected to the first bridge connection end and the second bridge connection end, respectively; a bridge sub-circuit board comprising a second substrate, and a third bridge connection end, a fourth bridge connection end and a third wiring portion for a first functional wiring on the second substrate, in which the third bridge connection end and the fourth bridge connection end are electrically connected by the third wiring portion, the bridge sub-circuit board being configured to be installed on the main body sub-circuit board by electrically connecting the third bridge connection end and the fourth bridge connection end to the first bridge connection end and the second bridge connection end, respectively, so that the first wiring portion, the third wiring portion and the second wiring portion are sequentially electrically connected to obtain the first functional wiring; an outline shape of the first substrate being different from that of the second substrate.
 2. The flexible circuit board of claim 1, further comprising a first control circuit combination structure, in which the first control circuit combination structure is disposed on the main body sub-circuit board and electrically connected to the first wiring portion, or the first control circuit combination structure is disposed on the bridge sub-circuit board and electrically connected to the third wiring portion; the first control circuit combination structure being configured to provide a first electrical signal to the first functional wiring or receive a first electrical signal from the first functional wiring.
 3. The flexible circuit board of claim 2, wherein the main body sub-circuit board further comprises a second functional wiring; the second functional wiring is electrically connected to the first control circuit combination structure on the main body sub-circuit board, the first control circuit combination structure is further configured to provide a second electrical signal to the second functional wiring or receive a second electrical signal from the second functional wiring.
 4. The flexible circuit board of claim 3, wherein the first functional wiring is obtained by sequentially electrically connecting the first wiring portion, the third wiring portion and the second wiring portion, and one of the first functional wiring and the second functional wiring is used to transmit a touch driving signal, and the other of the first functional wiring and the second functional wiring is used to transmit a touch sensing signal.
 5. The flexible circuit board of claim 3, wherein the main body sub-circuit board further comprises a third functional wiring; the third functional wiring is between the first wiring portion and the second wiring portion; the bridge sub-circuit board is connected to the third functional wiring; the first wiring portion and the second wiring portion pass under the bridge sub-circuit board for connection.
 6. The flexible circuit board of claim 3, wherein the main body sub-circuit board further comprises a third functional wiring; the third functional wiring is between the first wiring portion and the second wiring portion, and an orthographic projection of the third functional wiring on the first substrate at least partially overlaps with an orthographic projection of the bridge sub-circuit board on the first substrate.
 7. The flexible circuit board of claim 1, wherein the main body sub-circuit board comprises a first main body wiring layer at a first side of the first substrate, and a first main body insulating layer laminated on a side of the first main body wiring layer far away from the first substrate; the first side is a side of the main body sub-circuit board close to the bridge sub-circuit board; the main body sub-circuit board further comprises a second main body wiring layer at a second side of the first substrate, and a second main body insulating layer laminated on a side of the second main body wiring layer far away from the first substrate; a part of the first wiring portion is in the first main body wiring layer, and another part of the first wiring portion is in the second main body wiring layer; a part of the second wiring portion is in the first main body wiring layer, and another part of the second wiring portion is in the second main body wiring layer.
 8. The flexible circuit board of claim 7, wherein the first main body insulating layer has a first via hole that exposes the first bridge connection end and the second bridge connection end.
 9. The flexible circuit board of claim 8, wherein at least a part of a wiring of the first wiring portion on the second main body wiring layer is electrically connected to the first main body wiring layer through a second via hole, for electrically connecting to the bridge sub-circuit board through the first bridge connection end; and at least a part of a wiring of the second wiring portion on the second main body wiring layer is electrically connected to the first main body wiring layer through the second via hole, for electrically connecting to the bridge sub-circuit board through the second bridge connection end.
 10. The flexible circuit board of claim 1, wherein the main body sub-circuit board comprises a first main body wiring layer at a first side of the first substrate, and a first main body insulating layer laminated on a side of the first main body wiring layer far away from the first substrate; the main body sub-circuit board further comprises a second main body wiring layer at a second side of the first substrate opposite to the first side thereof, and a second main body insulating layer laminated on a side of the second main body wiring layer far away from the first substrate; the first main body wiring layer comprises the first wiring portion, the second wiring portion and the first bridge connection end, the first bridge connection end is exposed by the first main body insulating layer; the second main body wiring layer comprises the first wiring portion, the second wiring portion and the second bridge connection end, the second bridge connection end is exposed by the second main body insulating layer.
 11. The flexible circuit board of claim 1, wherein the bridge sub-circuit board comprises a first bridge wiring layer at a first side of the second substrate, and a first bridge insulating layer laminated on a side of the first bridge wiring layer far away from the second substrate; the first bridge wiring layer comprises the third wiring portion.
 12. The flexible circuit board of claim 11, wherein the bridge sub-circuit board further comprises a ground layer at a second side of the second substrate opposite to the first side thereof; when the bridge sub-circuit board is installed on the main body sub-circuit board, the second side is closer to the main body sub-circuit board than the first side.
 13. The flexible circuit board of claim 12, wherein the bridge sub-circuit board further comprises a second bridge insulating layer laminated at a side of the ground layer far away from the second substrate, the second bridge insulating layer is provided with a plurality of openings exposing a part of the ground layer, and the plurality of openings serve as the third bridge connection end and/or the fourth bridge connection end, for electrically connecting the bridge sub-circuit board to the main body sub-circuit board.
 14. The flexible circuit board of claim 12, wherein the bridge sub-circuit board further comprises a shielding layer at the second side of the second substrate, and the shielding layer is laminated on a side of the ground layer far away from the second substrate.
 15. The flexible circuit board of claim 11, wherein the bridge sub-circuit board further comprises a second bridge wiring layer at a second side of the second substrate opposite to the first side thereof, and a second bridge insulating layer laminated on a side of the second bridge wiring layer far away from the second substrate; the second bridge wiring layer comprises the third wiring portion, the third bridge connection end and the fourth bridge connection end, in which the third bridge connection end and the fourth bridge connection end are exposed by the second bridge insulating layer; when the bridge sub-circuit board is installed on the main body sub-circuit board, the second side is closer to the main body sub-circuit board than the first side.
 16. The flexible circuit board of claim 11, wherein the bridge sub-circuit board further comprises a second bridge wiring layer at a second side of the second substrate opposite to the first side thereof, and a second bridge insulating layer laminated on a side of the second bridge wiring layer far away from the second substrate; the first bridge wiring layer further comprises the third bridge connection end exposed by the first bridge insulating layer; the second bridge wiring layer comprises the third wiring portion and the fourth bridge connection end, in which the fourth bridge connection end is exposed by the second bridge insulating layer.
 17. The flexible circuit board of claim 1, wherein the main body sub-circuit board comprises a plurality of first bridge connection ends and a plurality of second bridge connection ends; the bridge sub-circuit board is in plural; and a plurality of the bridge sub-circuit boards are installed on the main body sub-circuit board by respectively electrically connecting a plurality of the third bridge connection ends and a plurality of the fourth bridge connection ends to a plurality of the first bridge connection ends and a plurality of the second bridge connection ends.
 18. The flexible circuit board of claim 7, wherein the main body sub-circuit board further comprises a terminal with a plurality of first contact pads thereon; an end of each of a plurality of wirings of the second wiring portion is electrically connected to each of some of the first contact pads in the terminal in one-to-one correspondence; an end of each of a plurality of wirings of the second functional wiring is electrically connected to each of some other of the first contact pads in the terminal in one-to-one correspondence; an end of each of a plurality of wirings of the third functional wiring is electrically connected to each of some further of the first contact pads in the terminal in one-to-one correspondence; some of the first contact pads respectively electrically connected to the second wiring portion, the third functional wiring and the second functional wiring are spaced apart in the terminal.
 19. The flexible circuit board of claim 7, wherein the main body sub-circuit board further comprises a terminal with a plurality of first contact pads; an end of each of a plurality of wirings of the second wiring portion is electrically connected to each of some of the first contact pads in the terminal in one-to-one correspondence; an end of each of a plurality of wirings of the second functional wiring is electrically connected to each of some other of the first contact pads in the terminal in one-to-one correspondence; an end of each of a plurality of wirings of the third functional wiring is electrically connected to each of some further of the first contact pads in the terminal in one-to-one correspondence; some of the first contact pads electrically connected to the second wiring portion, the third functional wiring and the second functional wiring are continuously arranged in the terminal.
 20. A flexible circuit board comprising: a main body sub-circuit board comprising a first substrate, and a first bridge connection end, a second bridge connection end, a first wiring portion and a second wiring portion on the first substrate, in which the first wiring portion and the second wiring portion are separated from each other and electrically connected to the first bridge connection end and the second bridge connection end, respectively; a bridge sub-circuit board comprising a second substrate, and a third bridge connection end, a fourth bridge connection end and a third wiring portion for a first functional wiring on the second substrate, in which the third bridge connection end and the fourth bridge connection end are electrically connected by the third wiring portion; wherein the bridge sub-circuit board is configured to be installed on the main body sub-circuit board by respectively electrically connecting the third bridge connection end and the fourth bridge connection end to the first bridge connection end and the second bridge connection end, so that the first wiring portion, the third wiring portion and the second wiring portion are sequentially electrically connected to obtain the first functional wiring; an outline shape of the first substrate is different from that of the second substrate; the main body sub-circuit board comprises a first main body wiring layer at a first side of the first substrate and a first main body insulating layer laminated on a side of the first main body wiring layer far away from the first substrate, and the first side is a side of the main body sub-circuit board close to the bridge sub-circuit board; the main body sub-circuit board further comprises a second main body wiring layer at a second side of the first substrate and a second main body insulating layer laminated on a side of the second main body wiring layer far away from the first substrate; a part of the first wiring portion is in the first main body wiring layer, and another part of the first wiring portion is in the second main body wiring layer; a part of the second wiring portion is in the first main body wiring layer, and another part of the second wiring portion is in the second main body wiring layer; a second functional wiring is all in the first main body wiring layer, and a third functional wiring is all in the second main body wiring layer; the first main body insulating layer has a first via hole exposing the first bridge connection end and the second bridge connection end; at least some of wirings of the first wiring portion in the second main body wiring layer are electrically connected to the first main body wiring layer through a second via hole, for electrically connecting to the bridge sub-circuit board through the first bridge connection end; and at least some of wirings of the second wiring portion in the second main body wiring layer are electrically connected to the first main body wiring layer through the second via hole, for electrically connecting to the bridge sub-circuit board through the second bridge connection end; the bridge sub-circuit board comprises a first bridge wiring layer at a first side of the second substrate and a first bridge insulating layer laminated on a side of the first bridge wiring layer far away from the second substrate, in which the first bridge wiring layer comprises the third wiring portion; the bridge sub-circuit board further comprises a ground layer at a second side of the second substrate opposite to the first side thereof, and when the bridge sub-circuit board is installed on the main body sub-circuit board, the second side is closer to the main body sub-circuit board than the first side; the bridge sub-circuit board further comprises a second bridge insulating layer laminated on a side of the ground layer far away from the second substrate, and the second bridge insulating layer is provided with a plurality of openings exposing a part of the ground layer, and the plurality of openings serve as the third bridge connection end and/or the fourth bridge connection end, for electrically connecting the bridge sub-circuit board to the main body sub-circuit board. 